If the AI product is recognised as "derivative work" of a GPL-compliant project, then it must itself be licensed under the GPL. Otherwise, it can be licensed under any other license (including closed source/proprietary binary licenses). This last option is what threatens to kill open source: an author no longer has control over their project. This might work for permissive licenses, but for GPL/AGPL and similar licenses, it's precisely the main reason they exist: to prevent the code from being taken, modified, and treated as closed source (including possible use as part of commercial products or Sass).

Yeah, the GPL is deficient in that way and doesn't handle other hostile uses.