Actually, in some instances, the mehtod has partly changed to using multiple teams of collaborators. There are production teams like Stargate Music Productions that use separate teams for lyrics, hooks, recording, production as collaborative tools. There's a good article in the New Yorker called The Song Machine about Stargate.
"We always start out with a musical idea. Great effort goes into creating a solid melodic core. We both play the keyboards and program, but in general Mikkel plays the instruments and controls Pro Tools, while Tor has the executive overlook as well as lyrical input. However, we both are hands on and have no rules or limitations. When we have some killer beats and musical starting points, we hook up with one of our favorite topline writers, who gets cracking on the lyrics and melody. We make sure there's a lot of melody in the track, so it can inspire the writer. Together with the topline writer we work, often tweek and simplify the song, and never quit before we feel we've got a killer hook." -- Stargate
Obviously, this method has been used before, but now, you can have this kind of collaboration digitally, across continents, which changes things a bit.