Doesn't sound like they got the plug pulled. The conference is still happening, only the public is no longer allowed to hear what goes on in there.
Now that it's ultra-private and invitation-only, they'll probably drop the pretense of it being a "dialogue between activists and academics" and call it what it really is---a back-patting, recruiting, and strategy session.
FR needs a mole in there. Transcripts would be invaluable.
And the government needs to bug the entire place.
Bingo! It actually worked out quite nicely for them.