Both are done in Boston imo.
Perhaps.
It wouldn't suprise me if one or both return, however. I could be wrong but I believe Rask wants to end his career as a Bruin, and to do so in proper fashion. I don't think he wants to slink out the back door.
As for David, stranger things have happened, and there may be a "handshake deal" to leave the door open for his return.
The Bruins and their fans should nonetheless operate from the perspective that both are gone for good.
If that's the case, best to get on with it.
PS I am not a Marvel person, but enjoyed the first installment of "What If..?" yesterday afternoon. Good writing, good animation. I've always found the "What If's" of history intriguing, if practically no-go's in my particular universe.
And FWIW, I believe time is simultaneous, and that there are, in fact, myriad you's, myriad me's, myriad earths, and myriad universes. Can't prove it, though.