This Netflix page shows the CDN using FreeBSD 10 now, whereas in 2013 it was 9.x.
I doubted you will find the answer to your question on this forum or for that matter on any public place. That is a such high level business decision that anybody...
I'm not going to bother listening through all that. As far as content delivery is concerned, Netflix does that through FreeBSD and contributes to FreeBSD to help enhance that and for that specific purpose. So, Netflix most certainly did NOT move to Ubuntu from FreeBSD.
However, googling for "Netflix FreeBSD" will show the linked article as the first result.
Me either, no first page hits (didn't bother looking further) when I tried google, bing, ddg and ixquick. Only ixquick gave me a quora link as a second result and that was another question asking why freebsd was chosen over linux.Interesting. I don't get that link at all with "Netflix FreeBSD".
Google deliberately tailors its list of results based on your previous searches in order to present you with what it (a computer program) thinks you want to see. It's a terrible research tool. Google shows that Quora page as the second result for me---which is still almost as high as you can get, sure, but then the #1 slot is held by the official Netflix page stating that they use FreeBSD for their CDN. DuckDuckGo, my search engine of choice, puts that Quora page over twenty slots down.
Note that in both cases it's the Quora page that gets on the list----not an official announcement or the Shuttleworth video itself.
I would say, the engines that list it lower are the worse ones. But it’s a question of taste.
I know people who use non-tracking search engines.