The idea of Android addition is not intended as general propose emulation; but to give developer who deploy preferably on Android to being able to sell their product on potentially any PC (given that said PC can boot from usb: see recent lenovo bloop on booting from ssd).
Wine is a great project, but I wouldn't put this by default: while Android emulation is much more about keep a bunch of apks (which are basically zip file) in one folder; Wine is most about complete applications who are used to change the os and require special configurations.
Playonlinx and "Wine bottles" for each game may tend to growth bigger and bigger and, usually, the space on a usb key is very limited.
Lastly: Windows 10 is going to be a closed platform "ala" iPhone/PS4/xbone with it's own store bundled in the OS... any indie developer who stick with windows will soon find itself forced in the uwp (where, probably, other store like itch wouldn't be allowed: see recent effort to put Itch app in greenligh: see the refused app there ). I would say: give the wine (latest update with driver and optimization tho) as option and not integrated by default.
Windows 10 is going to be an "xbox experience", so I think it makes sense to promote more open platforms (Linux/Android) to fight back before being kicked out (see Valve with SteamOS)