Yeah, I think it was episode 2 that mentioned some people just disappearing to never return and others disappearing temporarily while they were being moved to hospitals and the Nerve Gear having capacitors or something designed to allow it to be unplugged for a few hours before it does the death shock to allow for that.

It seemed like it wasn’t a recurring thing, so most of the players in the game at the end of ep 2 must have been moved to hospitals (or had other life support options).