These points aren't totally true. If it's a work of fiction they don't have the same stringent requirements as nonfiction. You can have celebrities in your books, and use song lyrics if you want. Stephen king would be sued into oblivion if you couldn't since he prefaced most books and sometimes chapters with song lyrics he writes. Brett Easton Ellis has Tom Cruise living in Patrick Batemans building and the two share an elevator ride together, and in lunar park they have a whole conversation about Christian Bale playing Patrick Bateman. You don't need consent for these things, as unlike visual mediums books don't hold the same requirements.
They can't be the main focus of your story, and you can't have them say or do things that would impact their reputation negatively. But if Russ wrote a fictional story of a dude who loved Taylor Swift and his goal was to meet her? Sure. what he's doing now? If he ever sold more than 5 copies then he'd probably be looking at trouble. Chances are he's being so brazen about this because he's hoping he DOES get sued and will get to meet her in court and woo her.
But to say he can't make reference to or use lyrics is patently false.