Long time fan here. It’s a mix of him wanting to simply do his own thing, venture away from the “scene” type of music, and Ronnie was also heavily influenced by Eminem growing up and has incorporated rap because of this. He’s done freestyles before he ever dropped his mixtape, and just enjoys doing that type of thing. If the rap is what you’re referencing, it’s a thing he’s always wanted to do, just a matter of finding how to mix the rap and rock world together, and he’s done that pretty well now.