I'm all for debating Yates playing time this year, but the likelihood and redshirt consequences are fairly straightforward, imo.
1) Likelihood - perhaps this was said somewhere in the thread, but if you watch and listen to Ken's question to CDP in the presser, I think it's cut and dried that Yates is only going to play if convenient. In other words, don't expect a lot of snaps unless 1) LJ is deemed unhealthy to play and 2) the game gets out of hand. He said snaps for JG are a priority as well.
2) Redshirt consequences - His redshirt is not getting burned, and he's not going to lose a game of PT due to the Duke game. The VT and NC State games are projected to be close games, and we might be favored in the latter, so there's unlikely an opportunity in those games for mop-up duty, and way more unlikely that garbage time happens in both. Push comes to shove, you can pretty much guarantee Tobias or LJ will come in to preserve Yates' redshirt at this point. This is roster management, and if the coaches are truly high on Yates, they know better than to play him sporadically in 5 games in a meaningless season.