Naw i dont think thats selling out just because you do something for money doesnt mean you sell out.
They probably offered something he couldn't refuse. Or maybe it as something different wanted another challenge. Or he taught it was gonna be fun to work with different artist. I dont know Cant hate the man for doing it. It builds on his already Hall Of Fame Resume. Makes me respect him more.

but Producers cant sell out tho cuz they can cover multiple genres of music

"I just wanna fuck with the dude just on the strength that I know how to keep it ghetto with him and I know how to bring 50 into the forefront of what the streets want," Premier said. "It’s a good marriage."

well our talk is garbage here any of u remember something named integrity or values ?? an artists sells out when his diversity dies when he raps about the same shit all over again and he doesn't have the social culture to cover multiple topics an example is Jay-z his music is repetitive to me and an artist doesn't conform to nothing but his own mind and creation an example is J Dilla he made his art and he didn't care most artists now days pretend to be non conformists whit both their style and image but in reality they are very conformists and they conform to rather their corporate masters or to the current "trends"