OK I figured it all out:
The guys from OU (Drew, HTF, BRiMan) are planning, in october, doing all for WDW parks in 1 day... Possibly recording their podcast as they do it. HTF says looks like he'll be buying Disney passes soon because, well, in order to do the 4 parks in 1 day, he will need passes. So that takes care of that comment. As for the #greenlit, well, the guys were planning on how they can do such a chore, and on what day, and have finally come to a decision and approved of the venture. therefore m, GREENLIT. #Disney, #disneyworld means simply, they are going to Disney World, nothing more..
Then the fan community goes bonkers thinking he is hinting at major expansions coming... He tweets People acting like Eticket(s) be coming or something...
#greenlit because that is how people were acting... then tosses the #greenlit in there for some extra poking fun at the hysteria of the masses who think he really is hinting at something, and he laughs and laughs and laughs as he keeps tweeting Uni information and Potter updates.
Yes? No? Maybe? ah it was worth a shot... LOL