This has the nice "benefit" of also making Twitter useless as a real-time organizing tool ("We're at City Hall demonstrating against the new ordinance. Come on down.").
Edit: I can see a grey area for "{$speaker,$performer} now taking the stage at {$conference,$music_festival}". Particularly if its somehow a surprise
Edit 2: Imo as written it's not a good policy because there are probably going to be lots of harmless things in technical violation that get ignored, so it turns into a "we'll enforce it if we don't like you or what you're saying" rule
"I'm at City Hall demonstrating. There may or may not be other people because if there were, I haven't asked them if I can share their location or not. Come down and find out in person!"
See also: masking, Streisand effect