The thing with Weird Al, he does not parody people's work out of malice. It's his gift of taking others' work and putting his twist on it, that makes him so brilliant. If he did a spoof on Prince, it wouldn't belittle him in any way.
Matt Groening once said the best comic targets are people who can't stand to be made fun of. People can take themselves too seriously, and that could be a comic goldmine. Bill Cosby, Regis Philbin, for starters.
SNL did a brilliant spoof on him in 1985. Back then the big record was USA For Africa's "We Are The World". Big all-star charity deal. Michael Jackson, Whitney Houston, Springsteen, Bob Dylan, and a cast of thousands. Even Dan Aykroyd.
Everyone who was big in music was involved Except Prince. So SNL did a lampoon with Prince singing " I Am Also The World". One word: brilliant.
Prince declined to comment. At the time, there was actually a spaghetti company called Prince Superoni, and he was battling to put them out business.