it's not fixed its broken
Here's a quote from the pvp forum page : - Fixed Drain Punch with or without Leftovers (Note for Drain Punch Shane already checked it many times, its just visual glitch, so for now its not bannable anymore.)
so yeah.
I used milotic for a long time in pvp and marvel scale works just fine while sleeping. If you want to test it, simply have a friend cast earthquake on milotic, check how much health you lost, then try it again after you use rest.