usando imagens em publicação de livro

Yes. These are the guidelines for use: Adobe Generative AI User Guidelines.  These guidelines say that content created with generative AI features can be used for commercial use unless the product is in beta and it says it cannot be used for commercial use.  The only other thing to note is if you are using the free Firefly plan, you cannot remove or crop out the watermark, even if your use is noncommercial/personal only.  I hope this answers your question.