That right there is how to end the annoying pop-locks which make me wait 20-45 minutes to get into Trueflame, and other servers.
As soon as a player leaves Cyrodiil for any reason, and that includes going into IC, they are removed from the population. Yes, that means that you can be unable to reenter Cyrodiil like the rest of us should it be pop-locked for real, and that should be a real penalty for going ganking in the sewers as opposed to helping your faction on the campaign map. You can still get into the PVE portion of Tamriel from IC, so they're not completely stuck in IC.
Cyrodiil populations should be reflective of the actual people playing in Cyrodiil.