He may not control 51% personally, but the Pritzker family overall is estimated to hold approximately 49% of the economic interest in the company and due to it's dual share class structure (Class A vs Class B shares) it controls ~89% of the total voting power. Given that Thomas is sort of the elder Pritzker and has been Chairman for over two decades it might be fair to assume he has some sway over how the family, over all, might wield that voting power, no? Furthermore, Thomas' son, Jason Pritzker, remains on the board and one might assume he'll remain aligned with his father going forward.

I think it's a tad naive to believe the Pritzker family, with 89% voting power, doesn't hold considerable sway over the company, it's long term strategy/direction, and its decisions (e.g. acquisitions, divestitures, substantial investments, etc.). I would assume that the CEO, Mr. Hoplamazian, is pretty clear that he serves at the leisure of the family...

Regards