If White is concussed the calculus on the league's punishment changes IMO. Concussions are such a massive issue for the NFL right now, and they're a multi-billion dollar business that has always used player discipline as part punishment, part PR maneuver to protect the brand.
Regardless of where you stand on whether Gronk *should* be suspended, it's almost moot if White stays in the protocol for an extended period.
The NFL would suspend Gronk as essentially a business decision - it can't afford to look weak on concussions, period. It certainly won't want this particular hit (not only blatant and ugly, but outside the whistle) looped ad nauseum as just one more exhibit on how the NFL doesn't take brain trauma seriously enough.