Hi,
I have an update from this past weekend (April 16th) on
1) Leipzig Marriott, Leizpig, Germany.
2) Lounge open all weekend, but breakfast is served in the restaurant only on Saturdays and Sundays.
Full breakfast allowed, appeared on bill, but was removed without problems. You might want to check before if you´re considering mobile checkout. Lounge is still open, so it can be accessed for drinks including tea/coffee or some quiet time (with all the breakfast guests now in the restaurant).
This seems like another "improvement". They usually allowed both breakfast in the lounge or restaurant, then limited breakfast to the lounge. Now, it is breakfast in the lounge weekdays and full breakfast in the restaurant on weekends only.