In that situation, the game clock has stopped to allow the chains to reset -- when they are ready (even if it's just the box and you let the chains catch up later), then R does a silent wind, and U moves from the ball.
You are correct if A snaps the ball prior to the U moving, *then the game clock is also still stopped* which would be a DOG foul. However, it should also be obvious that A can't snap the ball while the U is standing in the neutral zone. This is fundamentally no different than last year, just that the 40 second play clock is running -- and if that dips below 25 before the silent wind, then we reset to 25 at the RFP and then it's *exactly* like it was last year.