Sure, it's entirely reasonable to expect an artist stick to their usual content and to be disappointed if they make something you're not into. It's also entirely reasonable to expect an artist to want to do something different from time to time, that you won't like absolutely everything they make.
It is not reasonable to throw a colossal fit right after one animation, or to act like the artist betrayed you or broke a contract binding them to only make one type of content when they dabble with something else.
Its because there's an annoying track record of artists dabbling with stuff then shifting their content later on
Literally
I've seen Game Devs on this site try 3D art then complete fuck up the development of their game cause they wanted to remake it
I've seen Devs on this site dabble in remastering elements of their games then fuck fucking the entire process of their game and remaking an already unfinished games
I'm not even mad at Nyl for changing his content as there's nothing I can do but I'm more annoyed at the unexpectedness of it when there's unfinished stuff that he shelved and annoying people who want MxF to be the norm
If there wasn't patrons of his who don't overreacted and act like "oh it's fine do whatever you want" then that would probably make him wanna do it more.
I have my futanari animator list to fall back on but stop pretending people in the threads have to like this decision. No shit he owes the people in the piracy forums anything but he definitely owes it to the people who pays him