That Adele collaboration is the most likely out of those you mentioned. They both like and appreciate eachother, and Adele is releasing a new album soon, so... I can imagine a Madonna collab too. Madge obviously loves Bethany, she was the one originally planned for that iconic kiss (too bad Pink only has 3 iconic moments

), and on Ellen, Mdna said she likes her without thinking a second. Also, Bethany stans for her so hard

Remember when she first met her on that TV Show? She was so starstruck

And yeah, apparently there's a rumor about a possible album too...