Microsoft is also ending/has ended the few important cloud-based services that support Nokia's S40-based devices. As of mid-2015, S40 still had almost double Windows Phone's global mobile user marketshare (according to StatCounter), so Microsoft's sunsetting of S40 services has a bigger global impact.
Both S40 and Windows Phone are in decline, though S40's bigger share is declining somewhat faster. Regardless, it's probably not good business strategy to upset over 4% of the world's mobile device users (S40) with premature termination of the few Microsoft/ex-Nokia services they do use. As far as I can tell, Microsoft is really not doing anything to help S40 users get to Windows Phone even if they wanted to go there. It's a major lost opportunity. For example, Microsoft could have: (1) held onto the Ovi Store (instead of outsourcing it to Opera where it's even more moribund); (2) provided a reasonable set of core, basic Microsoft services for S40 (notably Skype Chat, OneDrive with basic document viewing, and a basic Outlook.com client); (3) provided an S40 on-device application that keeps basic phone settings (contacts, calendar, bookmarks/favorites, text messages, etc.) synced across devices to smooth the path to Windows Phone; and/or (4) provided an S40 emulator for Windows Phone so that users could migrate as much or as little as they wanted. None of that would have cost very much to do or been hard to do, but as far as I know Microsoft took none of those steps. Consequently S40 device users are not switching to Windows Phone when they get new devices. It appears that, among S40 device users who are in the market for a new device, more of them are choosing new (or newer) S40 devices than are choosing Windows Phone devices! Google is winning most of them, though, primarily with Android One devices.
Of all the companies that should understand this phenomenon, you'd think Microsoft would. Don't orphan users! Give them realistic options to continue doing business with you, and they very well might! And if a 2.3% global marketshare business makes sense (Windows Phone), then keep shipping one or two S40 devices every year to hang onto as much of that ~4% marketshare as possible for as long as possible, with the sensible/inexpensive transition offerings I described. There is an ongoing market for a relatively simple mobile device with a truly long battery life and a more pocketable form factor, the segment of the market that Nokia dominated with S40. There's nothing wrong with that, and Microsoft should keep at it. (Microsoft is sort of doing that -- they still have a couple S40 devices on sale -- but they're not executing well.)