Disney owns ESPN and ESPN does a lot of work with the NBA. So that part makes sense. And yes, that is Kareem!
D-Wade, Mike Conley, one of the Lopez twins, Victor Olidipo, Aaron Gordon, and Adam SIlver were there as well from what I could tell in the pictures posted to various socials. Looked like a nice event.
And a TON of other players attended... I follow the NBA (mostly my hometown team) and the "stars" of official media releases were all hanging out with other less famous NBA players as well.
One example: Mike Conley was hanging out with Jeff Green and Brandan Wright at the Magic Kingdom.
It's the NBA off-season still, so I'm sure there are lots of players getting their family vacation time in right now.
And are there seriously people upset about this? Let's review advice I always tell my 5 year old: "It's OK if people like different things."