The place they were seems to be the void from Loki. There is the 20th century fox logo and alioth. Also in front of the ant-man helmet there were cameos from Lady deathstrike, azazel, toad and callisto (plus we had Pyro in the last trailer)
I don't doubt that by making it it will be a good tribute to Fox's Xmen saga, seeing some villains. It is possible that in the final cut. If we have the return of some classic Xmen like Halle Berry, James Marsden, Famke Janssen. with their classic suits. 🔥😍