I agree too that the alternate history where Freddie would have lived would have been quite different for Queen.
Let's face it, death makes you immortal and a legend, and prevents you from doing fuckups. What would have happened to Nirvana had Kurt lived? probably they'd have released albums that didn't live up to the classics, they would have split up, Dave Ghrol would have founded Foo Fighters anyway and Kurt, dunno, maybe he'd have a lackluster solo carrer and by now he would be a fat, balding has-been. We'll never know, 'cause Kurt is forever young and tied to the three classic Nirvana albums.
Same with Freddie - I love Queen but come on, the '80s output was not on par with the '70s and it was more stripped down and commercial. They probably would have continued to have acceptable / mostly good album with the occasional great song, like The Miracle was (and if Freddie lives, take away one of their best songs off Innuendo, The Show Must Go On)... depending on the quality of their albums, by now they could have been on the same level of Bruce Springsteen and U2, just "another" big act with their following and the occasional new album no one but the diehards care about and the summer tour when they fill stadiums and that's it.
Freddie's death made him a legend and made Brian May and Roger Taylor the "survivors" in a sense, just like Paul McCartney is a walking musical god and the only living proof (sorry Ringo, I know you're still out there) that once there were the Beatles.