If you have a Pro account on Vimeo they allow you to replace videos whilst keeping the same link/view count etc. It's definitely easily done. I always wonder why YT has never implemented it for public use (as far as I know).
For the same reason that you can't edit tweets. You'll post something that gets a lot of attention, then swap it out with something controversial and the direct opposite from the original thing. Then it looks like the controversial thing is popular and all the people that initially interacted with it liked/retweeted it.
This is why I was genuinely shocked that even the Linkin Park page was able to swap videos. With hackers out there, nothing is safe anymore.
What's really astonishing about the video is that the band (and Chester) really seem to had a lot of fun during the european tour. It's crazy that it ended up this way. I just feel lucky that I managed to be a part of it (as I've been at the show in Monza) and watch them live at least once before it happened.