Here's the very brief Microsoft statement:
Software update service discontinuation for Nokia Belle and Symbian phones
Software update service for all the Nokia Belle and Symbian phones will be discontinued at the end of December 2015. The phones will no longer be able to receive Over-The-Air (OTA) software updates or software updates via Nokia Suite.
Given how long it's been since every other Nokia-provided service for Symbian was shut down, it's a miracle that all this was still working at all up until now. There's certainly no love for Symbian within Microsoft and all the Symbian enthusiasts within Nokia moved on to other companies before Microsoft took over.
The reality of smartphone use in 2016 is that it's not enough to be a great 'converged' device anymore - there's an expectation of being able to hook up, to share, to connect, and all of this requires support from the various online services. Which is where Symbian has fallen down, mainly because of the abandoning by Nokia of development of the OS.
PS. Although I'm posting the odd story to AAS and still own my own (bought) white (and Delighted) Nokia 808 PureView, it's only really a reference and play device these days. With the arrival of the Windows 10 Mobile-powered Lumia 950, we now have imaging that exceeds the 808 for everything except extreme zoom and Xenon use cases, along with better specifications and performance in every single regard.