A bit early to make predictions before the last sneak peeks,but as of scenes:
1.Calypso(tbh,now I feel like it won't be a penetration scene,maybe something like bj)
2.Penny
3.Dalia + Alex
4.Luna
All of them seem obvious,but also cause doubts at the same time.
Hard to say really. I was surprised to see Nova get both her first penetration scene AND a part in the first threesome in the previous update. So for all we know Luna or Calypso could go down a similar path and get more than 1 scene each. I'm perfectly happy to have more Penny/Dahlia/Alex scenes but all of them already have a bunch of scenes, including full penetration.
As far as threesomes that have been hinted at in game already I think the most obvious so far have been Dahlia + Alex and Luna + Annie. I would say Luna + Annie have been hinted at the strongest since Luna sees the future and saw a pretty obviously naughty vision involving herself and Annie.
I think Calypso is guaranteed at least 1 scene based on where the previous update left off. What kind, no idea but I would guess oral. I think there might be open revolt if Luna doesn't cash in her V card next update too so I assume that's a lock as well.
If I could get my wish list for 4 scenes it would be this:
1. Calypso 69 with MC
2. Luna penetration
3. Dahlia + Alex threesome
4. Annie + Luna threesome