Sailed on M class ships since 2004. Deck 10 aft is, and has always been AFAIK, the bar outside the OceanView buffet. Not a walking track.
There are still meeting rooms on deck 3, perhaps a bit smaller but definitely still there. On Summit and Infinity, Tuscan Grill has been added where there had previously been storage/kitchen. The plant conservatory, pretty but severely underused, is a specialty restaurant.