Horwath
Legend
I don't mind dropping or keeping medium armor, but I do think its high time we get away from a variety of armors with differing ACs. It never works, players are always choosing the best armors to get their AC.
So I'm good with more static AC armors, and then use secondary qualities to make the armors distinct and interesting.
Maybe then go with 13th age-like solution to armor?
Fighter/paladin:
Light: 14+dex
Heavy: 19
Barbarian/ranger/cleric:
Light: 13+dex
Heavy: 17
Rogue/druid/warlock/bard
Light: 12+dex
Heavy: 15
Wizard/sorcerer/monk:
Light: 11+dex
Heavy: 13
Heavy armor gives disadvantage on stealth and reduces speed if you do not have 16 strength.
A half-feat can be made that bumps up category of armor by 1 step better.