Yup, either you own it, or you don’t own it and ownership is being redefined as a quasi license.
There might be a few exceptions, if you really guided your model in a certain particular way, but that is rare.
What /could/ be is that you violate their ToS. If that ToS is valid and legally and practically enforceable is a different question and will depend a lot on your jurisdiction.
It’s kind of like causing what Google Docs autocomplete sentences helps someone write is still.. theirs.