And even if that's false, is still pretty easy to set up the implementation to be generated HTML that works on any modern browser.
The know nobody wants to use Bing, this is just another shady move Microsoft.
http://www.theverge.com/2013/8/15/4624706/google-blocks-wind...
There were, in fact, at the time, various 3rd party YouTube apps that worked perfectly well and were completely within the scope of the TOS - I personally preferred Jasmine on iOS to the official client.
Microsoft, however, decided that they were a special snowflake and didn't need to play by the rules. In fact, they also removed ads from YouTube -- Google's source of income with respect to YouTube.
Google was no doubt snipping WP. But Microsoft was in the wrong on that one - which just made it easier for Google. And the reason MS didn't want to do an HTML5 client for WP (and didn't want to admit it either) was that the HTML5 implementation on WP was not good enough to run YouTube reasonably. So they put themselves in the spot of either admitting an inferior browser or violating TOS. Either way, they made it easy for Google to hurt them.
I'm sorry, but there's no way to be on Google's side during that fight. It was a purely anti-competitive pissing contest. You don't have to be on Microsoft's side, but there is no legitimate way to say that Google wasn't abusing their dominant position over a competitor when it came to how they behaved in the early days of Windows Phone. There was a pattern of outright hostility. Google even said "we know where our users are, and they're not on Windows Phone". Since I was a Windows Phone user, I took the hint and stopped using all Google services. It's petty nonsense, and we all got enough of that in the 90s.
With respect to Google calendar - that indeed was a retaliation at Microsoft. Your story would be more complete if you mentioned that at the time, Microsoft was both threatening android makers with patents AND charging Google for patents related to Exchange services. While the timing probably was decided to best hit WP, I heard dropping exchange was planned a while before.
Incidentally, microsoft's response was "no, no, no! You don't have to pay exchange patent fees anymore, just let WP users use Google services again". And I am happy to report that, as you know, Google ignored that plea. Microsoft has been subdued into an almost reasonable market participant position - and I suspect this fight is one of the reasons.