I could see if they did this for one server or two but not for most, Vanilla is to much of a time sink, and people face burn out. I know i did Lvling a warrior 1-60 like 6-11 times gets tedious on 1x.
Personally i’d rather just have them do a hardcore PVP server, you die from anything there goes everything. I mean if you want risk reward that’s way more fitting then just resets.
Your idea isn’t bad, it’s just more work for blizzard, on something most people don’t want or care for. People want a Static game or the majority seem to.