Microsoft will end OneNote support, and the app will no longer receive new features and security updates. As such, users are strongly recommended to migrate to OneNote for Windows desktop app

Is this the UWP version, or just the "windows 10" version?

The non-x86 version is absolutely awful and deserves to die - the desktop version is fine, and not a bad tool for organizing notes and taking meeting notes when your company uses Microsofts tool house (i.e. you have no choice).