One more time, although phased trains do count against the train limit and so might have to be discarded to the bank pool.
This is incorrect. Phased out trains do NOT count against the train limit, see 6.83 (GMT rules).
6.83 Train Limit: The numbers of trains which a corporation may own varies with the game phase. *Phased out trains do not count against a corporation's train limit.* (emphasis added)