When I upgraded to Windows 10 yesterday, there was a screen that came up that asked me if I wanted to reset the default apps. I said no for my browser and media player, and when it completed, Chrome and VLC were still the default applications. I think it's a little underhanded, but not as underhanded as the article suggests.
Mozilla is whining anyway; when they switched search providers from Google to Yahoo I had to go through and specify it on EVERY INSTANCE of Firefox I have. Since I use --no-remote and segment my web browsing this was actually a royal pain in the ass. Granted, Google was the old "default," so I had never changed it, but it was still an undesired change in behavior. If they're going to whine about Microsoft doing the same thing then they ought to look at their own behavior.
Firefox is still my browser of choice for personal use but for others I've started to recommend Chrome. It's just less hassle to support it for your luser friends. The future of Firefox and Mozilla is not an encouraging one, which is a pity.