By the way, I wasn't able to reproduce issues with accepting the Ottoman flip and still seeing unit flips after declaring on them later. If you play as a civ that encounters the Ottoman spawn please make sure to keep a save from before the initial spawn decision and report in case the unit flips persist later into the game.
Will do, if I ever play as Byzantium, Rome, Greece (Which I wonder can the Turks claim by new spawn cities from Core holders like Greece/Byzantum? Can anyone do this? Cause as a player I know couldn't get Constantinople, not even if for example Holy Rome owns it, with a war.