I'd actually like if his grounded Wizard's foot was buffed to beat out projectiles instead of clanking with most of them; it would make many matchup's better. It also goes with his design to attack forward directly instead of having to dodge/defend.
Also, if they reduce the startup and endlag(grab or not) of Dark Dive, it could be used more safely OoS (instead of normal grab) and you could actually follow up after it, also would be harder to punish for recovery.
Reflect on jab is something I've also wanted for a long time, since it comes out the fastest of his grounded moves and makes sense for his character (OoT boss). After a long range projectile is reflected, it gives Ganondorf more stage control and time to approach.
What if they made aerial Flame choke like Fox's illusion?: instead of putting him into special fall, just give him a set amount of time before he can do another move. It would help recovery and offstage gameplay.
If they give him anything, just please make his downsmash reliably combo into itself, and fix some of the action lines on his moves.