It's an interesting theory...
I guess I'd argue that "creativity" isn't really a well defined "skill". Almost everyone's job involves some form of creativity.
The author's Steve Job's example doesn't really support his point as well as he thinks it does. The "muscle" of creativity may just be having a lot of diverse experiences (Like 10,000 hours of diverse experience?), similar to the "muscle" of engineering may be studying, building and tinkering for many many hours.
Same with the soccer/basketball example. The two sports aren't really all that different especially when you look at comparing something like golf and basketball or soccer and tennis. It's not super surprising that the "experience" created by playing soccer for many years would fairly easily translate over to basketball with small differences that would throw other players off their game.
The problem is the definition of creativity as a "skill". It's a really hard fit...
The main point that creativity is not a tangible skill that you can explicitly train for is spot on, but the turn from the 10,000 Hours Rule to the importance of diverse experience is a little forced because he is comparing two aspects that operate at totally different levels.
At one level, the 10,000 Hour Rule is a method for doing intentional work towards a specific skill or acquiring deep knowledge of a specific subject. At a higher level, creativity emerges from having diverse experiences and drawing connections to create novel solutions. It is not a skill that you can practice. The 10,000 Hour Rule can certainly be applied to specific skills and experiences that will ultimately and directly contribute to your pool of experience and knowledge that creativity draws from.
Applying deep and purposeful work towards something reinforces how quickly and readily you can connect it to any other kind of experience. So I would actually argue that the 10,000 Hour Rule applies very directly to creativity, just not in the way the author positions it.