Smartphones count as creation machines because people create content on them. If you take a look at Tiktok, Instagram or many of the other social networks, you'll see countless pieces of content that are created by smartphones each day.
If content creation devices aren't the devices that create content, then what are they?
I think that's a very good question. It's clear that devices like that are useful for some form of content creation, but I'm don't know if the term to refer to them has been coined or not.
Intuitively, they don't seem to fit in the category we used to call "content creation", since that nearly always was synonymous with creation+precision, rather than "any kind of creation".
Have fun writing a novel, designing a presentation, remixing a song or making a video game on a smartphone.