Up until like a year or two ago, YouTube links always used to be pretty clean. The format was youtube .com/watch?v=[video_ID]. A year or two ago, they started adding a tracking suffix on, so it would be youtube .com/watch?v=[video_ID] &si=[tracking_ID].
Over the last day or so, I’ve noticed links with a different format, youtube .com/watch?v=[video_ID]&pp=[tracking_ID] - only the pp= string is much longer than the si= string. This can only be because they’re including more information in it. What that information is is anyone’s guess.
This is basically a PSA to watch YouTube links more carefully, as people are by and large complacent with them (moreso than other links) and never even realised the si= change, let alone this new pp= change.
It could also be that the change to pp= is meant to circumvent communities, like this one, which automatically filter out the si= suffix. They may have decided to address that, then took the opportunity to make their tracking more severe.
I know, that is the idea
https://openuserjs.org/scripts/Kraust/Youtube_Embed_Redirect
Little script with few bytes, I installed it as extension. It redirect embedded when I click on a YT link or open a video in a new tab. It0s more confortable as edit the URL by hand, the script don’t do other than this. Apart you can watch it in full tab size, better quality and without ads. You can search the Video also with Andi and watch it there embedded and sandboxed in the search result.