In Rae's Breakfast Club interview, the way he explained it was they he, RZA/Leo's people had multiple meetings to try to work out the logistics. But in order to set everything in motion for his series, he had to sign off on by a set date, that they would've missed if they did a movie. RZA told a similar story as well. In the book, he acts like RZA brushed him off completely. Their story is too big and too many characters for a 2.5 hr movie anyway. If Rae had his way, he would've cut Deck, Uey, MK, prob GZA out completely...hell, he prob would've reduced Power's role as well.
According to RZA, he said they are welcome in the writer's room and on set at any time...they just don't come. Ghost be paranoid when they call up asking for input about that ish, Shameik at one time was speaking to Rae pretty frequent. GZA and dude were vibing for a while, having him along for a couple of shows. I'm not sure about the rest.