To be released from the seat would require a conscious action from the crew member to unbuckle the seat harness. If they were ejected from the aircraft whilst still attached to the seat, I think the impact forces required to do that would not be survivable in any event, and if ejected whilst still attached to the seat they'd probably sink and not float to the surface
I don't think that's completely true - think of the two survivors off the BAH BV234. They had no idea how they arrived on the surface.
Apologies if I'm breaching etiquette, but has anyone seen reports that indicate the pilot was responsive at the time of rescue? I only ask because a few military veteran coworkers' general response to the reports of "critical condition" was that this was SOP if SAR crews did not have someone licensed to pronounce at the point of rescue, and so the condition is not changed to "deceased" until reaching the hospital and the attention of full MDs. Is this generally correct?
I suspect you are correct as I was quite surprised to see the initial news briefings saying so openly that "things weren't hopeful".