Avengers #672

I'll bet that the Legacy Iron Man series picking up the numbering at #593 will stay like that at least to #600. But if this Legacy Avengers series makes it from #672 to #700 without having another #1 restart it will be unusual in modern Marvel. Although going weekly for 12 issues from #675 will make it more possible.

Viv is the only surviving member of the synthezoid family Vision created for himself in his 2016 series - wife, son and daughter. There was also a synthezoid dog which 'died' in #11 but was reanimated in #12 and I think Viv still has it.

Olympus Station was the HQ of the Olympus Group, secretly the Greek Gods. They featured in many Hercules series including Incredible Hercules with Amadeus Cho. Cho inherited the corporation after the Olympians left in Heroic Age: Prince of Power #1. So his team the Champions could use it, starting I think in #1.MU.

Nadia-Wasp changed her surname from Pym to Van Dyne with Jan-Wasp's permission in Unstoppable Wasp #8.

There have been at least 2 Counter-Earths.
The 1st was created by the High Evolutionary in Marvel Premiere #1 - the 1st appearance of Him as Adam Warlock which led into his own series set on that planet. This C-E was stolen by the Beyonders in Marvel Two-In-One #63 and allegedly destroyed by Thanos during the Infinity Gauntlet story
The other was created by Franklin Richards in a pocket universe to house the Heroes Reborn characters after the Onslaught event. In Heroes Reborn: Doom Dr Doom of the main reality transported it from the pocket universe to the position of the old C-E. This version was last seen in Exiles #81-82.
Then High Evolutionary appeared in the 2015 Uncanny Avengers series as ruler of a C-E which was only occupied by his New Men. It is unclear if this was a new C-E recently created by him ir if it was 1 of the previous C-E's. If it's a new 1 what happened to the Heroes Reborn C-E? If it's 1 of the old 1's what happened to their previous occupants?
We have hints here and in the solicit that this story involves HE and a C-E, but we'll have to wait to see if it's the C-E from UAv. But remember that all previous C-E's were before the multiverse was destroyed in Secret Wars III, so this could be a whole new ball game. But on the other hand Nova and Spidey remember going there.

But I'm not sure they have!
Spider-Man was with many others on Paradise Omega during Infinity Crusade but that was another planet, created by the Goddess and temporarily put in the C-E position in a time between the above 1st and 2nd C-E's.
Nova (Sam Alexander) has had a few brushes with the High Evolutionary, but I don't think he ever went to a C-E.

The Primer pages were as usual edited by Darren Shan and written by Robbie Thompson. Daniel Acuna did all the artwork and it was lettered by this issue's letterer Cory Petit.