This is by all indications the world's most expensive acquihire of a single person. Reporting has been that Zuckerberg has seen Wang as a confidant of sorts, and has proposed a vision of AI that's said to be non consensus.
Wang didn't get $14b, he only owns about 15% of Scale. We also don't know how much he sold. He could have sold all of his stock (netting him around $4.5b), none, or something in the middle.