Hex warrior increases accuracy, lifedrinker adds more damage (hex warrior adds cha-str, so something like 2 usually. Lifedrinker adds cha, so 5)
Hex warrior also increases damage. It specifically states you may use CHR INSTEAD of STR or DEX, for Attack AND Damage rolls. Yes, lifedrinker doesn't make your attacks more accurate (that would be broken, though honestly, it's easy enough to do anyway especially in BG3 with your own farts giving you advantage). The point here is that you already get the standard desired martial setup all in one with Pact of the Blade now, as in CHR now handles all your melee damage stuff with your pact weapon which can be anything, but if you really want to for whatever weirdo reason, you can still use Str or Dex as normal. Lifedrinker is good because it basically doubles the damage you get from your modifier, which is still fantastic.
In any case, it is also unclear to me whether Larian is actually using this for BG3. The Italian article does not say much, and it appears to be fairly confused about how Warlocks work NOW, so I am not sure how far to trust it (to be fair, the problem may just be Google Translate). My confusion stems from the fact that they say that Warlock does not get an extra attack, but this is untrue due to the fact that blade pact does get access to thirsting blade.
It would be really easy for Larian to just apply charisma mod to attack/damage for blade pact weapons, add the thirsting blade invocation, and then leave everything else pretty much the same as it was in early access. But maybe they did something else? We'll find out on August 3.
Imo it'd be splitting hairs no matter what they do. They've homebrewed so much already this is barely DnD 5E. Frankly, they're going to need to shore up this more than you seem to think, though, as warlocks that go pack of the blade should be able to get medium armor and shield proficiency too, just like hexblades do, so either way it's gonna blended into pact of the blade or maybe thirsting blade or it'll be its own incovcation with thristing blade being part of pact of the blade and just given you extra attack at 5.
Again, splitting hairs, same difference, and I think it's okay to lose a few hexblade features or make them have an opportunity cost to obtain because you're already getting patron features the hexblade didn't get.
