swvaughn,
I'm not a Black Pearl author but I can answer your question. I write Urban Fiction. Black Pearl publishes Urban/Hip Hop Fiction exclusively. I've done extensive research on the UF/HHF industry. After being burned by PA, I learned to do my RESEARCH. The beauty of learning things the hard way is that we never forget, but I digress...
The reason BP asks for that format is so they can print the ms AS IS. If you look at Triple Crown's submission guidelines, you'll note that they, too, have "oddball" formatting criteria. Again, if they like the ms, they can print it AS IS. If you do the measurements, you'll end up with a ms that is pre-formatted into either a 5.5x8.5 or 6x9 template. Melodrama Publishing also has "unorthodox" submission guidelines.
Unfortunately, this is the case with most UF/HHF publishers. Lack of editing, or shoddy editing at best, is one of the biggest complaints about this genre. (Many don't consider UF/HHF a genre, but those who write, publish and/or read it do). It is not unusual to open an UF novel and see the typeset is double-spaced throughout the ENTIRE novel, typos galore, (--) not changed to emdash, words underlined rather than italicized, edges unjustified, and so forth. I won't even get into the "bootycall" covers.
In defense of UF, a lot of it is self-published so, perhaps these self-pubbed authors don't know any better, rather, haven't taken the time to educate themselves on the business and production ends of publishing. So, I won't come down on those authors because they're only hurting themselves. However, I will and DO come down on the CRAPPY UF/HHF half-a$$ publishers who send mss straight to press - they are hurting others (writers).
This isn't my first time hearing these allegations against BP. They've been all over other forums, which are predominately comprised of Black and Latino writers, for months. In most cases the authors have come forward and posted their experiences firsthand. IIRC, one of the cases is presently in court (I believe in GA). Perhaps that explains why the authors directly involved can't comment.