On Hexblade: Wyll's ability score distribution doesn't fit the character, unless they either make him a hexblade or fold Hex Warrior into Pact of the Blade. In which case hexblade becomes redundant.
I think they are going to modify Pact of the Blade.
I agree, I think this is quite a likely implementation of pact of the blade. I can't see them providing you with a physical item.
It's such a trash pact boon that doesn't really mean anything to anyone other than hexblades. Also putting "charisma is your attack stat + medium armor" behind a level 3 hurdle makes it much harder to do the exceedingly common Paladin X/ Warlock 1 hexadin build.
I think it's extremely unlikely multiclassing will make it into BG3.
In addition to all of that, the lore very clearly established Wyll's Patron as a fiend and not a talking weapon. That said, Critical Role made Fjord's patron a leviathan, but he was still a hexblade, so who's to say what sort of limitations Larian would take seriously.
Larian seem to favour standard PHB fluff over the "refluff it how you like" approach that WotC take.
