It's definitely that one.
Several other conventions at the same venue confirmed they're going on as planned around the same time Otakon did.
Basically, that means the venue operators told them "You WILL be holding your convention this year, on the dates you scheduled, otherwise you'll pay the penalty in full."
Otakon (nor any of the other cons to be held at that venue) has no way of weaseling their way out of having the con this year whether they like it or not.
I think at this point it's pretty much common knowledge that force majeure isn't a thing anymore, and most cons from here on out are happening. I'm not sure if the doomerfag posters genuinely don't know this, or a just "pretending" to be ignorant.