I doubt you'd find a rifle produced today, or way back in time for that matter, that had the wood behind the butt plate sealed. First thing I do on any rifle(or shotgun) I acquire, is take it down completely and seal all unsealed wood with tru oil. And I'm not talking just the butt, remove the stock from a remington 700, you'd be surprised at the amount of unsealed wood around the action. Seal it completely, then put it back together, and I've never had a point of impact change. Just my personal opinions and thoughts, unfortunately, gained from getting older & older.
Sincerely,
Garry