There is no need to guess, it’s stated.
“I’m currently analyzing with different attorneys and advisers the steps to take next. One of the pieces of advice they gave me were not to give any names to avoid escalating the situation even further. It pains me to do so, because I feel I need to warn the community so that this doesn’t happen to more people. But I understand this is the way things work and right now I need to trust that the justice system in my country will do its work.”
I watched this unfold on twitter, and in the organizer's defense, he only addressed the situation and the culprits after those people started a public discussion regarding the ban. The organizer was defending himself.
Moral of the story: Strike first, strike hard, no mercy?
More reasonably but still on the aggressive side, does this mean that now we have to publicly announce when speaker invitations are rescinded to get ahead of the story?
At first glance, it kind of does. Although it makes you wonder what you'd actually put in this public announcement. Would you simply state the facts (along the lines of "sorry, but X isn't going to be speaking after all.") or would there be more detail (read: speculation) included?
I don't really think there's a way to win this. In the event that you're wrong, it'll blow up. In the event that you're right, it still probably will blow up, depending on whether that person (or their fans) go on the offensive or not.
The only actual winning move is not to have played (only inviting people that you know, doing advanced due diligence on anyone a degree of separation away), but are you really winning if you do that? It would seem to seriously limit your horizons.
I think it is wise to publicly announce both speakers who have accepted invitations and speakers whose invitations were revoked (don't even have to say they are revoked, simply stating "unfortunately John Doe will not be speaking in our conf" should be sufficient). If not for these situations, then simply to inform visitors whom they can expect to hear in the conference.
As he is pursuing legal options, I’m guessing his counsel told him not to.