I always leave it turned on. Respawns don't happen all that often and when they do, it just adds a new twist to the game. They respawn immediately.
If you had an embassy with that civ, you have to establish a new one if they survive & a civ can only respawn once.
If you had an embassy with that civ, you have to establish a new one if they survive & a civ can only respawn once.