I am a fan of Bubba Wallace and I can't see him faking this. That would end his career and he doesn't seem that stupid.
Think, think about it he has a Black lives matter themed car, he was been out spoken in the Confederate flag ban and black rights. NASCAR as a sport is filled with bigots, fans and employees. There are probably a lot of suspects. Probably not a driver, likely someone with access.
Yet I won't jump to any conclusions. I want to see how this story develops.