No, it doesn't.
The actual drinking animation is fine but the flex after is clearly a waste of time, from a gameplay standpoint its dumb.
It's not, it's there so that you're punished for poorly timing a heal. For the games they're in, that design makes complete sense.
For MHW, a game where you're probably going to be on the move frequently with monsters even being able to chase you a long way, it probably didn't make much sense to force you to stop and devote time to healing.