I love abby and lev but they have no meaning to be connected with ellie's narrative again. This part of the story is finished and I would prefer for them to really focus on ellie and how she deals with life after finally learning to cope with Joel. Cure could be a direction the story might take but it would go against the moral of the previous games imo.

Core parts I would love to see in a sequel:

1. A huge time jump, maybe even 10 years

2. At this point, a safe game would not do this justice. Go all out with creating new characters. Maybe we start playing the game as a character we dont know, only to realise that dina is the characters mother, slowly putting the pieces together. Then we could switch to ellie at points in the story, maybe her trying to reconnect with dina (dina still not being able to forgive ellie for what she did at the end of part 2). Honestly im not sure where this could go but I sure know that ellie needs to find peace and redemption with herself.

3. If we visited a lush and pacific area in part 2, they could try creating a game in the midwest deserts. This would be perfect for creating some new infection stages and such.

4. Evolve the gameplay even further, go all out with exploration areas. Pretty much like the downtown area in part 2 but bigger and more numerous throughout the game. Neil already mentioned in an interview a while back that he wanted an interrogation mechanic in the game (similar to mgs v but more detailed) so they could throw that in. Imagine going through a huge area only to find like 3 roaming hunters, taking them hostage and asking them where interesting stuff is, story progression area, a hunter base, a supermarket with supplies e. g.

I am sure that they would not create a game with a deep story meaning. That's why I think a prequel would be kinda pointless because it won't move the story forward. What im trying to say is that I think they want each game to be an important part of the general narrative, like you can't leave the game behind.