Microsoft has moved across the Lumia support section for software updates to its own website. Previously available on Nokia's online portal, it makes sense for Redmond to move things across post-acquisition of the Nokia handset division. Consumers interested in finding out just when they can expect to receive future updates will now need to head to Microsoft's website, or load previous locations to only be redirected across.
If you've not used these sections before, you'll see us refer to them when we're talking about software upgrades, be it major Windows Phone releases or bundled firmware updates. It's a better experience to have everything available for consumers to quickly check through, instead of having to release multiple articles to detail the same piece of information for multiple regions.
Just make a mental note that everything has moved home and we're good to go. Oh and it's not just Lumia either, as all Nokia update stuff is now on Microsoft's website, including the Asha series of phones.
Source: Microsoft; Thanks, Anders M., for the tip!