See D16677#214911.

• ConpherenceThread->hasAutomaticCapability() effectively disables the policy self-checks by skipping everything.
• If we stop doing this, we run into problems because adjustObjectForPolicyChecks() doesn't know how to predict participants.
• If it predicted participants correctly, you would be unable to leave rooms ("can't make an edit which prevents you from making edits").

Users are hopefully not terribly likely to hit this especially often.