WotC (the people that write the rules of 5e) actually *sorta* changed how Polymorph works in 5e already.
Compare the spells Polymorph vs Mass Polymorph. Functionally, MP is just Poly but with more than 1 target.
Except Mass Polymorph now gives the target Temp HP. When the Temp HP goes away, the target reverts to their original form. Small change, but it does make the mechanics a little simpler (and makes it so you can't stack Temp HP on a Mass Polymorphed target).
Last edited by Isaac Springsong; 10/10/20 05:55 PM.