Madead will always have Like a Virgin. Kids have at least heard that title somewhere. They also might have heard their mom singing along to Holiday or Vogue on a throwback radio station. She'll definitely have something when she dies.
Blowie has nothing. He's not even a nostalgia act since no one regardless of age seeks out his old music to begin with or talks about him in any regard. Look at how long the media held onto the deaths of MJ, Whitney, and even Amy Winehouse. In his case, it seems like he's just gonna be another person to tribute during award season before everyone moves on and is done pretending to care.
She's a darling and we do adore her in the UK but Madonna as always been above her.