I don't see how they do a post-ending expansion unless they either:
a) Pick a canon ending (do
not do this)
b) Let the player choose/create a new character
c) Actually deliver on the promise of Lifepaths and have different paths through the expansion depending on your ending
A good point was brought up in this thread re: Johnny still being stuck in your head pre-ending, which makes me wonder if they might actually go for a post-ending or prequel expansion, as I don't see them being willing to pay Keanu to come back and do more voice work. A prequel would likely be messy, since then you'd level up your character only to be brought back to level 1 at the start of the game?
They may just decide to use a different character entirely. If they do eventually go for a sequel to CP2077, it would face a similar challenge as a post-ending expansion anyway, so the easiest approach would be to drop V as the protagonist.
Another option for a mid-game expansion would be to have some contrived way of removing the link between V and Johnny for the duration of the expansion. Or just get a different VA for Johnny?
I really hope they take up the challenge of a post-ending expansion, trying to take into account all the possible different outcomes (i.e. 2-3 different paths packed into 1 expansion). That, I feel, would draw my attention back to this game again.
My second pick would be starting with a new character, but only if this time they focus more on character customisation. Not in the superfluous "can I have a tatoo on my junk" way, mind you, but customisation with actual consequences for the story and the path the player takes through it. Both plot-wise and game-mechanics-wise.
I'd want the expansion that turns this game into an actual RPG, basically.
Will be curious to see what CDPR decide to go with. If it's just more of the same, which - let's be honest - is most likely what is going to happen... well, I may actually skip it