I’m slightly surprised about some exclusions - mainly Benedict Cumberbatch, Benedict Wong, Brie Larson, Chris Pratt, Don Cheadle, Evangeline Lilly, Iman Vellani, Jeremy Renner, Mark Ruffalo, Tatiana Maslany, and Teyonah Parris. Most of those have been in post-credit scenes or in concept art (Pratt, Ruffalo, and Vellani have been particularly prominent there).
Sure, you can’t have everyone, but some exclusions - given some inclusions - are weird. I can’t see how you go to Kelsey Grammer and X-Men* without Teyonah Parris. Have any of those actors definitely said they’re not available?
*On the other hand it’d be a great fake out if Cummings, Grammer, Marsden, McKellen, and Stewart were playing completely different people.