Honestly, I feel like Warlock might be one of the classes that'll take more work than some of the others. It has a lot of very it specific mechanics with Eldritch Invocations, Pact Boons, and Patrons (which replaces subclass). On the surface Warlock looks fairly normal but then you get to a lot of abilities being utility and RP focused like GOO Warlock having telepathy. Then EIs have a lot of interactions that completely change mechanics, which so far seems fine with the EB ones but when we get pact specific ones things might get off. Pact of the Tome gives you Ritual spells which then brings up the problem of ritual casting not being in the game. And then they'll have to make a whole new mechanic for pact of the blade where a warlock can summon any weapon and make any magic weapon their summonable weapon (which might really mess up the inventory system). So I think it's not just GOO warlock that'll need fixing.
(And I'll spare everyone here my summoner rant on how pact of the chain has been implemented all wrong)
