What if they didn't want to give users a way to iterate quickly through various attempts at obfuscating copyright content by just the right amount in order to bypass the copyright screening?

Not saying that was the reason but it's not implausible.

It would have been baffling to me in the past, but I've felt it's pretty clear that YouTube is more interested in catering to mainstream entertainment giants rather than individual content creators. It's baffling they'd even bother with this now. The only reason I can think of why they would introduce this feature is that their algorithm has been backfiring on content creators they are politically aligned with.

I’m pretty sure it was in a backhanded way. I would upload a video and keep it private. Then you could wait and see if any part got flagged. If it didn’t then you could publish.

I am guessing, because of the complexity of the problem. With the previous way of doing things I am guessing youtube either push all the videos that get uploaded in to some queue to detect copyright violations, or once a video reaches a certain number of views the copyright algorithm gets triggered.

With the new system I am guessing they have to do this thing in real time and almost anything real-time is a complex problem to deal with right?

Agreed... and it makes you wonder why Google held back on this.