If it's specifically Games for Windows then it will. If it was an older game for say Windows XP it's a hit or miss. Some will be detected by the Games Explorer and some won't.
Thats true. But most people associate game controllers like that (yes the dualshock controllers fit the stereotype perfectly) with games. A picture of a mouse and a keyboard would specifically point to computer, not computer games.
It doesn't surprise me that Microsoft managed to sneak something like this in there. I guess they were targeting the same crowd that was vulnerable enough to fall for Windows Mojave