Long story short: That pop-up you get when you open Firefox (or whatever other browser) for the first time asking you if you want to make it your default browser won’t work anymore. They’re forcing you to go through their convoluted control panel where you have to change it like 20 times for each file extension.
Microsoft wants the Year of the Linux Desktop ™ to come quicker.
Microsoft will get away with this like they did hundreds of times before due to their dominance and the overwhelming apathy of the average computer user