Calm down unicorn bros, lets calmly point out the facts, don't listen to the anti-unicorn gays dressed up as unicorns nor the homo beggars.
Unlike her "friends", Irys has never made a collab with the homos, not even when the lean addict was pushing her hardly to do it so why break that now?
My conclusion is, there was a lot of money behind this, Activision/Blizzard is trying to promote their dead game as much as they can and at the same time make it as interesting as possible so I wouldn't be surprised if they even set the rules of what they want.
TL;DR It is very clear that this is a mandated collab and the girls have little to no freedom on what to do.