A $250,000 convention is, e.g., 250 rooms at $250/night for two nights plus $125,000 in catering. That's a really big event to leave for a random staffer to negotiate, with any benefits accruing to the organizer rather than the company.

In any event, Hyatt properties can't negotiate anything when it comes to the WoH program terms, so this is likely to be a bonus points and/or cash commission type of situation.