I would honestly be so here for it, they really have nothing to lose! Either that or we need a movie in which they play arch-rivals who become friends at the end.
I know Mariah can be bitchy, but I think at her heart she's a good person who's just been through a lot of shit and who'd rather be petty about things than angry about things. She's actually had a pretty hard life, you just wouldn't know it from how she presents herself.