This is really all that needs to be said. I was in high school and the military during the height of Missy's popularity, and I've never heard her name come up in a serious rap discussion.
She was looked at as a unique artist/visionary, not an emcee. She's like in the Michael Bivens category and there's nothing wrong with that.
Missy is still a rapper. You're not going to hear Missy's name come up like that because she's not lyrical. It's the same reason you don't really see names like Busta talked about.
Nobody looks at Missy like no Michael Bivins. That's a gigantic reach if I ever seen one.