Celebrity actors VA in games is a fairly recent development. For much, much longer we had random people doing VA even without getting a credit. Even now, celebrity VA is not very common and only happens in few AAA titles. Very few people will notice if games get back to the old ways, IMHO. The only thing this strike can possibly do is to screw its members from any game VA gigs.
It seems to me that if the SAG wants to play hardball with video game studios, they'll quickly find that the studios aren't as beholden to them as the TV and movie studios are.
If studios wound up having to use entirely non-union actors it would lower quality, but it would be survivable. Certainly there's a lot of old-school games done by very amateur actors, tolerably.
Celebrity actors VA in games is a fairly recent development. For much, much longer we had random people doing VA even without getting a credit. Even now, celebrity VA is not very common and only happens in few AAA titles. Very few people will notice if games get back to the old ways, IMHO. The only thing this strike can possibly do is to screw its members from any game VA gigs.