This link is to a Mastodon thread which links to another blog post which links to an actual source on ynetnews.com which quotes another article that has a quote from a YouTube rep. Save yourself the trouble and go straight to that article (although it's not great either): https://www.ynetnews.com/tech-and-digital/article/bj1qbwcklg

The key section:

> Rene Ritchie, YouTube’s creator liaison, acknowledged in a post on X that the company was running “a small experiment on select Shorts, using traditional machine learning to clarify, reduce noise and improve overall video clarity—similar to what modern smartphones do when shooting video.”

So the "AI edits" are just a compression algorithm that is not that great.