Uh... no... the convention center was never set up as a shelter site. People just started showing up there.
I would not be surprized, given the state of official channels of communication, that some people were told by LEO or others who "seemed to know the scheme" to go to the Convention Center.
Today, people started showing up at I-10 site, in busses and in military vehicles, and the "peopel in charge" could not figure out why that was happening.
So, some fluid stuff happens - and the rescue and relief operation should be able to react to a mile or two shift in location of a mass of people.
Uh... yes.