I don't think so, as we we've never been kept in after previous games in Munich, or even after Schalke, Hoffenheim, Hamburg, or Dortmund.
Leipzig was the only exception, and I still don't why, especially as I'd been to the same stadium just a few weeks earlier, when the Stuttgart fans were deemed trustworthy enough to be allowed to leave after the Final Whistle
Just be mindful that the Allianz Arena is roughly 30 mins on the train from the hauptbahnhof, and that's before you factor-in the walk to the nearest metro/queues etc
It was a similar story in 2014-15 when our 1-0 defeat clashed with the Oktoberfest and all the hotels were ridiculously expensive. I'd booked a train journey, not dissimilar to yours, and only just made it