I don't know how much it does for immersion since this is the first time we're hearing mention of genies in any context, but I agree that it's probably just a throw away joke.
Hopefully not. I didn't need this subclass, but in principle it would be a wasted chance... But maybe they already considered it for a later DLC.
I would love to see a new dev blog about better and more interesting motion captures for e. g. archaic weapons: slingshots, whips, blowpipes and hopefully bolas (https://www.dandwiki.com/wiki/Bolas_(5e_Equipment) --> my Bounty Hunter needs that to catch his prey alive).
The new sneak attack animation was a shot in the dark, unfortunately.
I would also be luckily surprised to see a Dire Raven familiar (for the Raven Queens' Hexblade) and melee sword'n'shield Skeleton Warrior familiar both for the Pact of the Chain. That could be a nice tribute to Ray Harryhausen. Much respect for his passion. It took him four months to produce his memorable and iconic skeleton scene, which runs, at most, three minutes. It's a timeless pleasure to watch it:
