Imagine a paying Adobe CC customer.
They use Firefly to generate a poster, and unbeknownst to them, the image it generated is a reasonable facsimile of a copyrighted/trademark character.
The person has inadvertently committed copyright infringement.
So does Firefly need to come with a warning?
The safer solution, to the chagrin of another commenter, is for Adobe to neuter the tool by only training on data in which Adobe has express permission to use.