A skilled copywriter will easily "tweak" the text so that it looks more like it was written by a human. Honestly, that's what it looks like the most to me.
This also could be the case. But if the author is going through the trouble of doing some re-writing, that's OK with me personally, as it means they at least put some thought & time into it. If just one or two words are changed, they add the words "I personally believe" at the beginning, or they add extra punctuation or something cheesy, that's still bad.
This technology's just going to keep affecting things more and more. The quality of content on forums and such is gonna change big time as these generative AIs evolve and get better, and they will. AI detection tools catching bot writing already proven unreliable by giving false positive results. Plus there's already tools rewriting bot posts so they'll trick AI detection. Not sure how we actually stop this down the road.