Myself and at least one other guildie tonight experienced Cyrodiil without keeps. I've attached an image of BRK below, and as you can see, all the structural parts are missing. And you could walk through the space where the keep walls would be, although it did force you to slow walk when going through those spaces. It also as possible to attack through where these walls would be. Additionally, the keeps were missing on the Cyrodiil map, including when trying to rez, so rezzing up is not a possibility with this bug. /reloadui did not fix the bug, only relogging did.