It's hard to tell whether the lounge closures have been at the will of the individual properties or due to pressure from Marriott, but I think many of us view the closures less as following the rules but rather as doing the minimum necessary to stay compliant with MR's T&Cs!
Not sure how many are "closures." My guess, based on personal stays, is that most non-resort fs properties have not had weekend lounge hours for years. A number used to be open on weekends, and are now closed. One or two used to be closed, and are now open. Some with closed weekend lounges comped breakfast in lieu, but have discontinued that practice. Others which did not comp weekend breakfast in lieu, now do. Some which used to comp weekend breakfast, but then announced discontinuance, have recently reinstated the benefit, as I found out my last stay at the Marriott Westfields. And lastly, there are the properties that may or may not comp weekend breakfast in lieu, depending on who checks you in at the front desk and what their mood is. (I'm talking to you, Renaissance Toronto Downtown).