I’ll have to say Procreate does seem like an amazing animation program if one goes by all the bells and whistles on that site. I do see one “Achilles Heel” with the program and that is limiting the implementation to the iPad. One thing Animation Paper and all the other animation programs have going for them is being able to run on various platforms.
I’ve done animation on everything from flipbooks to drawing on film leader. It is a craft with no limitations. Digital is only one more way to make the impossible possible. Will Procreate become another toolset for the modern animator will remain to be seen. We have more than enough tools to work with as it is. It can only get better.