[fjtorres]

1- Skydrive has been Onedrive for a while so that is probably legacy code.
2- With the growth of Cloud computing a lot of hardware and software is becoming brand agnostic. For cloud storage that means transparently supporting Google, Dropbox, Amazon, and Onedrive, at a minimum. Baidu, Box, Mediafire, and others are being hard coded into apps, too. If it has significant presence, it's supported.

So no, it isn't odd to see references to any or all in Android, Windows, or Linux software. It's just accepting reality: that's what people are using to store data for mobile devices and there's no point in annoying the paying customers.

(Interesting to see Kobo using Overdrive's back end for this. It suggests other ebook vendors can do subscriptions, too.)