Now you are making me more confused.
Lets say Realm A lost war. Realm B says you must give City to Realm C. If said city is last city of the realm, but Realm A is at peace with Realm C.
Options are fake war with realm C or Realm B destroy city and TO it and then hand it over to C. Which is not very nice if City happens to have a lot militia and infra built. It would be easier to declare fake war with realm C than first TO by realm B and then hand over it to Realm C. It would wreck a lot regions on every party.
I'm not sure why the fake war with C (and then having C TO the region) is better than having B TO the region and then hand it over to C.
Either way, though, this still fits the "surrender" scenario, in my view, even though it's handing over the region to a realm that didn't actively defeat you. I would consider it highly unlikely that surrender terms of this sort would have C be a realm that was A's friend, so the "fake war" would be real enough that they didn't at all like each other.
The kinds of things I was thinking of were along the lines of realms trying to merge to get stronger, or the days of realms trying to use fake wars to avoid TMP penalties (not that that helped much).