"This video is currently unavailable"

Is there a specific reason that most YouTube videos used in the stories result in "This video is currently unavailable" when I try to play them back? As best I can tell, I'm seeing this because I don't have Flash installed, but I do have a browser capable of HTML 5 video playback, either via H.264 or WebM. Every time I see the message, the same video works fine either in a Flash enabled browser, or on an iOS device.

My understanding is that this is usually caused due to YouTube wanting to serve an ad with the video. They haven't updated their HTML5 player to support ads, so they lie to the user in an attempt to get them to either use Flash, or just assume the video truly isn't available.

Checking my own YouTube videos, I see an option marked "Monetize your videos and grow your audience. Become a YouTube Partner today!" I'm assuming this is where the creator of the video can say they want ads.

I respect the Verge if the reason is that you do truly want YouTube ad revenue for the review videos here, and will just deal with not seeing the videos. However, I wanted to raise the issue to ensure it was intentional, vs an accidental setting that could be fixed to allow Flashless desktop users to see the videos.