I think the issue is around intent, and it is not an easy issue to resolve, either morally or legally. There are many legal precedents in music - for instance Tom Waits won a case against an ad agency who, after he refused their request to use his song in an ad spot, used a "sound-alike" song in their ad. When an AI is being used to knowingly circumvent paying a creator for their work, that does seem problematic - but likely unenforceable except in clear-cut extremes.