I just replayed the 2nd game. I heard they want to break S2 for the events of the 2nd game, into two seasons. That will allow them to expand on some of the individual stories, similar to what was done in S1, as there are two distinct sections. First they have to show Abby's motivation. Then Ellie's. You switch back and forth between the two in the game, but that may not work as well in a show. Then things come to a head. That last part may move into S3.
Druckman has not confirmed there will be a 3rd game, but indicates he intends to continue the show. A 3rd game seems very likely still, but zero word about it.
I don't mind Bella Ramsey as an actress, but I agree that she's maybe not an exact fit here. He is looking for their personality to suit the character, not the appearance. Though some of the other actors fit pretty well, not all of them do. The actor for Abby looks very much like her, except for the obvious fact that she's a few sizes smaller lol. In the game, she's taller than and more muscular than Owen. In the show, she's a foot shorter than him. The actor for Jessie looks pretty close. The actor for Tommy is completely different than the game.