Dave, back when I was in college I accidentally ran 5 .30-06 rounds through the washing machine. Fortunately I caught them before going into the dryer.
These were handloads in new brass, R-P brass and WW large rifle primers.
Much to my surprise, all 5 rounds fired!
I'd suggest that the hunting conditions would have to be pretty extreme to beat what happens inside the washing machine. Can't see any harm in sealing them but don't see much need either, after that episode.
Shotshells for waterfowl hunting are probably an entirely different story, I would be afraid of using steel shot if the crimp wasn't sealed. Sure wouldn't want to shoot a bunch of steel that had all rusted together.