They strongly implied this in previous interviews over the past 2 days but it seems it has been outright confirmed now with WCCFTech. There is a new ending in the expansion. If I was a betting man I'd say it's a 'you cure yourself' ending. So many people wanted a 'happy ending' even though that totally contradicts the cyberpunk genre. So CDPR probably gave it to them. I hope, if I am correct, there is still a deep cost to the 'cure' story wise. To stay true to the message and themes of cyberpunk. None the less here is a snip;
With Phantom Liberty, are you picking up from one of the endings of Cyberpunk 2077, and if so, which one?
No, this takes place in the midst of it. You get to a certain point in the game and this unlocks, but of course, we let you skip right to it much like it was done in The Witcher 3's expansions.
It's the same thing as it takes place during. Now it has endings, different endings based on how things play out. Then, based on the ending within Phantom Liberty, you can unlock a new ending in the base game.
Ok. So is there just one new ending for the base game, or are there going to be multiple, depending on multiple endings of Phantom Liberty?
There's one new ending in the base game because there's already a bunch in the base game endings. But there's a new one that has to do with your new relationships and characters and situations here.