The moment in question is edited in Apple's video though

That doesn’t appear to be true to me.

I watched the portion of the keynote from Apple’s feed and a couple other videos and they seem substantially the same. The sound’s actually better on the Apple video so I can hear the rumble (not really “boos”) more clearly.

Can you explain what you mean?

No, that's not true. I checked about the day after the keynote: the moment on Apple's recording of the event is exactly the same as the moment was on the live stream.

It’s easy to prove that your statement is incorrect. John Siracusa posted on twitter that the segment where they announced the stand was 56 frames - a little less than 2 seconds.

How is it edited, and is it the only part that's edited?

I don't know if it's just me, but i'd rather not direct a monetizable view to the perpetrator of (what I consider) copyright system abuse for the very event they bottlenecked/dammed/funneled the views towards their channel during.

Awkward sentence, I know. I can't think of more simplistic way to put it this early in the morning.

You think Apple is putting third party ads on their WWDC keynote?

They won’t even take marketing money from Intel to put the garish stickers on their computers.