My assumption was the uploader wanted to make the creator's "AIGC" less obvious. It definitely did that to me.

Yeah, that's a weird one. I doubt the video was generated that way. I assume someone flipped the video for "artistic" purposes.

Reversing text is a known loophole to getting around copyright guardrails in image-generation models.

How does that work? Would you prompt the model to write "hello Kitty but in reverse" on the train so the resulting image isn't flagged?

Much more likely they just flipped the video in an editor after it was generated. Its common enough to see flipped video with backwards text on social media, most people wouldn't give it a second thought.