I have beaten the game with the Minutemen, leaving the Railroad and Brotherhood still alive.

Desdemona talks about Glory being dead, as does Carrington, but she is still alive since I didn't do railroad quests far enough for the brotherhood to attack the railroad. Glory is walking around the Railroad HQ perfectly alive, but she won't say anything.

Also P.A.M talks about Brotherhood being destroyed and their ''remnants'' needing taking out, but the Brotherhood are still perfectly fine.