She's Madonna, the woman is above every single person in the music industry (unless you're a Beatle), too big for that show, it's like getting McCartney on it.
Madonna isn't above doing statement promo like this in the UK, and the XF final is the closest thing our market has to a music slot like the Super Bowl Halftime. This would only help solidify her legacy and help her appeal to the younger generation. Unless of course the performance is awful or she performs a wack new song. I could see why she wouldn't want to take this risk.