Last year, LeVar Burton strongly suggested he would be returning to Picard, but now it's a "maybe." Gates McFadden also stated last summer I think, that there had been "discussion" about her appearing. But two things to keep in mind: COVID may have changed things, and also my understanding is seasons 2 and 3 are basically going to be shot back to back.
Yes I thought that was the situation about certain actors appearing in seasons 2&3 .But due to Covid they have to be really careful about older actors appearing in Picard.
The original plan was to do Seasons 2&3 back to back, in an interview Akiva Goldsman refused to confirm that was the case. I actually hope they are. It would mean a shorter wait between seasons, and Sir Pat can go back to London or New York and do some theater afterward.
Back in December, Production Weekly (an LA Industry Magazine) had Star Trek Picard season 3 filming dates as June 2021 - November 2021 which may have been pushed back slightly because season 2 was supposed to start in January 2021 but didn't begin filming until February 2021.
John deLancie confirms they are working on both seasons right now: https://trekmovie.com/2021/04/30/jo...h-of-a-very-different-q-for-star-trek-picard/
So far for TNG members on PIC we have: Yes: Riker, Troi, Data, Hugh, Q No: Beverly, Guinan, Worf, Geordi, Wesley, Pulaski, O'Brien/Keiko, Ro. Beverly & Guinan are the most central to Picard's life in the TNG era.
While it turns out that this is just Dorn returning to voice Worf for a game, if I had a preference, I'd prefer we see Worf on Lower Decks. I just think Worf would be the perfect foil for the humor on that show.