They are going to need hexblade if they actually want Wyll to be an effective melee fighter. As he is now they've already fudged the rules a bit so he can wield his rapier. Even if we never get hexblade, they need to give us the actual warlock's pact boons, which we should already have, because they come in at level 3 (and get rid of the weird integrated pact boon where chain pact is somehow only attached to fiend patron, and great old one gets nothing).