The use of LLM is different because it is a new disruptive technology that has not been properly accepted by society and does not have the proper laws yet. People are losing their livelihood over it, so it is not like using free assets on unity marketplace.

Considering all the debates and lawsuits around LLM using copyrighted work to train their data on, you could put in your listing that assets were generated with LLM. You are transparent from the get go, the people that will be mad will get mad, but at least it will be upfront.

If you don't announce that you used LLM and people figure out that you used LLM assets, the backlash risk being greater than announcing upfront that you generated assets with a LLM.