Mighty Avengers #23

Loki mentions being trapped in a tree and on the Isle of Silence. The 1st refers to his 1st Marvel appearance in Journey Into Mystery where he had been imprisoned in a tree until someone sheds a tear for him. The 2nd is where he's been banished at the start of Avengers #1. (He'd last been seen in JIM#94,96 chained to a wall, but that obviously hadn't kept him out of mischief.)
He also mentions creating the 1st Avengers, but that was accidental unlike this team.

Thor Annual #10 explained how all the Elder Gods apart from Gaea became evil, and the Earth was populated by their demon children - continually at war with each other. Gaea created Atum who absorbed the demons and evil Elder Gods, became the Demogorge and flew into the Sun. Much later humans were born, and new gods.
A few Elder Gods like Set escaped their fate. Chthon did so by fleeing to another dimension. But before he left he wrote the Darkhold as a link to return.
Chthon claims here that humans used to worship him and he ruled them through fear - but later generations forgot him. However he left Earth long before the rise of Man. His worshippers would only be a select few mages. But he was able to do things from his dimension and supposedly created many demonic species.

Jonathon Drew and Herbert Wyndham discovered large uranium deposits in Mount Wundagore in Spider-Woman #1. They used it to finance the High Evolutionary's citadel. But radiation made Jonathon's young daughter Jessica ill, which eventually led to her becoming Spider-Woman.

Jocasta was created by Ultron with Jan-Wasp's mind in Avengers #162. Henry Pym presumably took Ultron's brain-wave transfer equipment after his defeat. (Ultron had previously used the same technology to give Vision the brain pattern of Simon Williams/Wonder Man.)

Iron Man refers to Stature and Vision as kids. They are both in the Young Avengers. Stature is the daughter of Scott Lang/Ant-Man. Vision's kidhood is not so straightforward. He has the operating system of the original Vision but his brain pattern is that of Iron Lad, the young Kang the Conqueror.

In YAv#11 Super-Skrull told twins Speed and Wiccan (Tommy and Billy) that they are the sons of Scarlet Witch. Research into what happened to Wanda's twins suggested that they would have to be reincarnations if anything. In YAv Presents #3 they tried to find her, unsuccessfully but they did find some confirmation.

A lot will happen before #24 but Jarvis and US Avenger won't make any appearances before then. Quicksilver will also rush straight there to join the team to be near his sister Scarlet Witch. The rest of the YAv (Hawkeye (Kate Bishop), Hulkling, Patriot, Speed and Wiccan) will also be among the missing until Stature and Vision invite them there to tell them about SW (but the MAv will get whisked off to several issues of adventure before S&V get a chance).
The rest of the main cast will be busy:-
Stature and Vision will sort-of appear within Captain Britain & MI-13 #10-15 as Dracula tries to take over the UK, but they're actually an alternate timeline version. The real Vision will be at Thing's wedding in the 2nd half of Fantastic Four #569, and Stature will show up in Incredible Hulk #601 as Bruce Banner is declared Hulk-free.
The alternate versions of Jocasta and Wasp will also be in CB&MI13. The real ones will also be in FF#569, and Wasp in IHu#601.
Amadeus Cho and Hercules will take some Hulk time in Planet Skaar: Prologue as Hulk's son Skaar come to Earth. But Herc will be in FF#569 and then both will be with Stature and Wasp in IHu#601.
These issues show that S&V are already part of the new MAv, and have presumably informed the YAv. And the MAv are continuing but in these instances without 'Scarlet Witch'.

Loki will be back as Wanda in #24, but she has been even more busy as Loki in between. She's in PS:Pr as part of Osborn's Cabal, in the final issues of the current Thor series plus Thor God-Size Special. Then in Dark Reign: Cabal she makes a deal with Dr Doom, and as Thor picks up his original numbering with #600-602 she getts Thor evicted from Asgard and leads the Asgardians to Latveria. Then back to the Cabal for DR: Hood #2 before pitching up in #24.

Norman Osborn is the only other character from this issue that will return for the next. His apps in the meantime are too numerous to fully list but he is in some of the issues mentioned so far, plus some others that mark the next apps of some other chars from here:-
His 1st app is within Agents Of Atlas v2#1-5 as they pretend to build weapons for him. This is the next app of Captain America (Bucky Barnes) and Wolverine (and the rest of the New Avengers). (Wolvie has also got too many other apps to tarck after this.)
He follows Iron Man into his #8-13 as IM goes on the run with the Superhero Registration database. Meanwhile Tony's given Pepper Potts her own armour.
He also follows Hulk into Hu#10-13, the last of this run that green Hulk shares with Red Hulk. Banner/Hulk then segues into PS:Pr (with Osborn too) and the Skaar: Son Of Hulk series (including a visit by NO). Then Hulk/Banner transfers to Incredible Hulk restarting with #600 of the original numbering, where it is Red Hulk that takes the Hulk out of Banner.
Meanwhile alternate NO even gets into the act in CB&MI13.
The real Osborn has a meet with Loki in Thor#600, and again in DR:Hood#2.
There are lots of other less relevant NO apps mixed in with those.

The CB&MI13 issues are obviously the next apps of Black Knight, Captain Britain and Spitfire.
She-Hulk and Thor's 1st apps after here are cameos in Wolverine (2003) #73. But Thor then moves on to his own issues as mentioned for Loki.
SHulk continues in SH: Cosmic Collision where we meet Thundra and Valkyrie again. She and Thundra will also show for Thing's wedding.

Other chars won't reappear until after #24:-
Crimson Dynamo will pop up in Red Hulk's next issue (#14) of his now-solo Hulk mag. Then in Hu: Winter Guards he will rejoin Darkstar and Red Guardian but will be replaced by a new CD.
Modred will be 1 of the possibilities in NAv#53-54 for the role of new Sorcerer Supreme. Brother Voodoo gets the job, the new name Dr Voodoo, and his own mini-series where Modred will show up in #5.
Sasquatch is reunited with his old Alpha Flight buddies when they get resurrected in Chaos War: AF.
Meanwhile Guardian (Michael Pointer) will get another rename to Weapon Omega and join the Norman Osborn's Dark X-Men in DXM: The Beginning #2.
Bova's next app is to get killed off by her creator High Evolutionary at the start of the New Warriors (2014) series.
Chthon will attend a meeting of demons during Fear Itself in Journey Into Mystery #627. Then he too will appear in the NW series as that team continue their involvement with HE in Wundagore.