You Were Opted Into This By Default
It looks like Adobe has been harvesting the art you create on all Adobe Creative Cloud apps to add to data sets being used for machine learning. The program was apparently started almost six months ago and all subscribers of Adobe CC were automatically opted in, with nothing in the way of details offered to users. Thankfully they have provided details on how to opt out here.
It is likely that some of the training data is being used to improve Adobe tools you make use of, like the 2D to 3D transform function. However it also seems probable that Adobe is feeling a little left out of the newest craze, and want in on it. With the popularity of DALL-E, Stable Diffusion and other AI art tools that can make a picture from a text prompt, it is hard to believe Adobe isn’t eyeing their own take on AI art.
With the huge amount of people using Adobe Creative Cloud every day, they would be able to gather a huge amount of data to build training sets for their own product. Adobe doesn’t gather personal info along with your creations, but it seems likely that with enough examples they could easily recognize your style and replicate it. If that doesn’t appeal to you, you should definitely take a look at your privacy settings.