"I don't think this is off-topic. If you draw the Penrose diagram for e.g. a Reissner-Nordstrom black hole there are null geodesics that allow light from other universes to be seen."
"While I agree that to answer this question would be pure speculation, I absolutely disagree that the Kerr Metric is non-mainstream. It is a well studied solution to the Einstein equations which is to be found in any graduate lecture course on Black Hole Mechanics."
My current suggestion were to change this de-facto policy, and repair its damages on the site by
- the removal of the lock from the questions,
- and to do a scan in the currently held/deleted questions, and do the same if there is the same case. Partially I could help in this, although I can't see the already deleted questions.