So that's what Fort Minor meant? I could have sworn Mike explained it as something along the lines of meaning it as a reference to something loud (Forte - Fort) and dark (minor keys in music being darker). I know that I'm not completely correct but I SWEAR I remember him saying something like that.
Ryu is essentially saying the entire concept of Fort Minor is down to Linkin Park and SOB (with the project's very name being a reference to them). Fort Minor was always Mike though, I've always thought that even since 2005. I thought it was Mike alone, but that he just featured SOB a lot. They were never official members of FM.
I'll be honest, I can see why he's let down and disappointed, but unless more is going on then this one verse being cut out, I don't see how Ryu feels disrespected to the point of basically saying he regrets putting so much effort into his collabs with Mike.
EDIT: Ryu just said on IG that Mike doing a one man show is like Paul McCartney touring solo as "The Beatles". There are so many things wrong with that statement....