So I don't think I ever officially added it to the rules, but I've pretty much considered it precedent that everything officially released by Nicki is article-worthy here while everything that isn't from her is not.
For example, Mercy (Remix) is unofficially remixed by Wayne and Nicki (e.g., it's not for sale, not cosigned by Kanye West, &c.), but since it's something actually put out by her, it's 'official' on our website, since everything revolves around her.
On that basis, if some rapper (famous or otherwise) remixes a Nicki Minaj song without her permission, I've considered it unofficial for this wiki's standards since it has nothing to do with her actually putting it out. The Lil Wayne remix of "Roman's Revenge" is official since it's on iTunes and she's making money every time someone buys it, while the Slim Thug remix of "Beez in the Trap" is unofficial since he released it on his own and, even though she complimented it, she had nothing to do with it.
Many rappers release many official remixes, both because it's profitable and very typical of rappers to go back and always try to spit a better verse and give others an opportunity to do the same. I thought the Wayne remix of "Roman's Revenge" was actually her only one, but I just discovered this gem on iTunes:
It appears to have only been released in the Commonwealth, so I guess that's why I never heard this before. Since this is an official Cash Money release, however, I guess we've actually found another official remix! Enjoy!