I know a lot of people see covers albums as the end of a career, but I don't really see why. She could do one covers albums and then go back to doing original material. Tori Amos did a covers album and then continued on with original albums.
I like her ballads, but I also enjoy the uptempo dance stuff as well. I don't think she should limit herself to just ballads. I agree Rebel Heart was a great album but it had uptempo dance, midtempo and ballads.
I don't think there's one Madonna. She's as much a fun dance artist who sings Girl Gone Wild as a softer ballad singer who does Messiah or Take A Bow. All of her albums are her.
I don't feel she should limit herself to just ballads.
If she were to do a slower album, I would like it to still have an electronic edge sort of like Frozen, nothing too AC with just traditional piano and acoustic guitars.
I heard the All Saints cover of Like A Prayer. I thought it was okay, it was pleasant enough, but didn't really blow me away. It kind of lacked passion, but it was nice to hear. Their voices are very girlish, not very distinctive to me.