Stanley Enow and Maahlox for a featuring? Nope, that could not happen, not yet at least since the two rappers are not on good terms. According to a member of Stanley’s team, such collaboration has not yet been decided. One of the rappers could be planning it, however.
So nope, the featuring is not for now, maybe in the future.
In conclusion, the poster announcing the two men’s collaboration is just a fake designed by someone who thought that his wildest dreams could be realized.