What do you mean? This group has had that element from the beginning, and he obviously is a huge part of the songwriting process. Why shouldn't he include the elements he wants into the music*?
*(assuming the other members aren't openly against that, but there's no evidence to suggest that)
That's my bad, actually. I haven't really followed this band all that closely, and that's mainly because I had heard that a few songs on the EP were diss tracks directed to WIM. Also, I just found their lack of a cohesive style to be a bit off-putting.