Ticketmaster found 12 family packs available for the game. Not a wise rumor to start because it could cause people that haven't purchased tickets yet to reconsider, fearing they we're too late?
UA has been known to use a scarcity marketing strategy in the past, they did it with me the entire summer trying to get me to renew. They posted several times about the scarcity for the soccer camps, and posted when they were actually sold out.
If the game was close to being sold out, we would have seen a post mentioning the scarcity.