I am against this!
The reason being, that hexblade was always intended as a fix for pact of the blade. Blade pact, before XGtE was by far the weakest of the three, and basically not worth taking. But since you can not edit printed material, instead of balancing the original problem, they introduced Hexblades as a fix for people wanting to play a Gish warlock.
Now, that is fine, and hexblade is one of the coolest subclasses in all of 5e. But we already know one sword wielding warlock. The blade of frontiers. Wyll is supposed to be this fantastic fighter, yet he HAS to be a fiend warlock for story reasons.
Instead of introducing hexblades, use the video game format, where you can make changes to rebalance the game (see Rangers, esp. Beastmasters and now Monks) and fix the actual problem, pact of the blade. Noone is playing Hexblade for the lore. What even is your patron???
Instead, use the hex warrior feature, and just add it to the pact of the blade. So take the pact, and you can attack with charisma and get medium armor and shields...
It is balanced, since you still need a ton of additional invocations to make melee warlocks useful (thirsting blade, lifedrinker, ...)
Also, this balances multiclassing, since one level in hexblade is no longer enough to get all the benefits, you now need 3 levels in warlock. Which is a substantially larger investment.
And finally, this means any warlock, including Wyll, can be a competent fighter, regardless of patron. You do not have to use a sentient weapon/ the raven queen all the time anymore, now
