Input languages don't require anything to be installed anymore, they haven't since Vista. All language versions of Windows support display and input of all the languages that Windows can support. So yeah, if you log in to this hypothetical Korean PC using your Microsoft Account it should be able to have Dutch and English input languages.
Right. So, yeah. That sounds convenient to me. The languages I write in don't change when I'm on different PC's, so to me it makes perfect sense that they roam around with me.