Jenifer Lewis in 'Hairspray'

So, I've always wondered why Jenifer Lewis did not originate the role of Motormouth Maybelle in 'Hairspray'. I know she did the demos for the show and she always says that the role was written for her (joking?). So I was always curious why she didn't end up doing it instead of Mary Bond Davis. Was she actually supposed to play it, and couldn't for some reason or was she just meant to do the demos?

And while we're at it, I'm still wondering what BJ Crosby's connection with Hairspray is, as mentioned by Harvey when she died.

https://twitter.com/HarveyFierstein/status/581611588567842816

Jenifer was unable to do the broadway show because she landed a role on the Lifetime show Strong Medicine. I'm not sure what BJ's affiliation may be except as a possible Motormouth in a workshop.

BJ would have made an incredible Motormouth! I can only imagine what she would have done with 'I Know Where I've Been".