For those that like to just

on producers for commercial success just because, I'm going to drop this in here from a legend:
Do you ever feel limited in by people calling you and wanting that signature DJ Premier sound?
Nah because I know that they know what that sound and the name attached gives them, so I get it.
On top of that, it's fun to do all styles of what I do ... I don't want to be just a hip-hop producer. I want to do a Miley Cyrus record, an Eminem record, an Iggy Azalea record because my version of that sound isn't gonna come out fukked. That's how much I worry about my name as an artist. When I go in with any artist part of my job is to make sure that it comes out way more than right. Jay Z and Biggie and Nas always listened to my direction. They listened and they applied it and I also listened to their opinions and that's why the records came out so good. They didn't come out because of luck … we're all good at what we do but it's also us all knowing when it's a good record that's ready to leave the studio. That's what I like about Dr. Dre, he said "I don't let nothin' leave the studio until it's really really ready."
DJ Premier Talks Kanye, Disclosure, and That One Time He Walked in on Biggie Eating Fried Chicken in His Boxers | NOISEY
^^^ and no I don't value Noisey on anything, but this isn't their opinion. These are DJ Premier's own words. So in essence, when you look at Timbaland's list, it isn't a list of producers who exclusively produce Hip Hop. It's a list of super producers, who are versatile enough to step outside of the realm that are known for. What's funny is that the Pop and R&B artist who tap Timbaland, Pharrell, etc. for production want a Hip Hop sound and what typically sounds like a Pop/R&B record. It's like someone calling Quincy Jones a Pop or an R&B producer just because his biggest records are with Michael Jackson, which completely ignores his roots in Jazz.