If a for-profit company were to be the one doing it a bunch, then I would start to take issue with it. It would feel like they’re milking somebody’s likeness from beyond the grave to get more money - even if they have good intentions. The only way in that case that I think it’s okay is if they’re given express permission to be able to do it. Such as JEJ giving Lucasfilm the rights to clone his Vader voice. They apparently didn’t handle this process right with Tarkin, as you might have seen in the news.
But, as Hal pointed out, not many actors have ever really weighed in on this AI topic properly. I think this is a case of it’s okay (for us) to do it so long as you aren’t financially benefiting until the actor/estate actually expresses they don’t want it done with them. And not doing anything inappropriate with that likeness along the way.
It seems like you’re approaching this from more of a spiritual/supernatural approach. Again, as long as the AI product is honoring their legacy and work, I think it can actually be quite respectful. It shows that they aren’t forgotten and can continue to have an impact on the world by continuing to develop their characters. I suppose a part of it depends on your willingness to separate the character from the actor, though.