They weren't invited...
But gay groups joined the queue for tickets - which were given out to families on a first-come, first served basis
My guess is that the "invited" guests were in a better location roped off from the public at large. But neither were they crashing, apparently.
so nobody was invited, then.
Not true. It's a ticketed event every year, open on a first come first served basis. There are no "special invitation, box seats" for this event.