Ample evidence gathered by Microsoft news outlets and the ever-investigative Reddit community confirms that the T-Mobile bound Lumia 810 won't receive the Lumia Black update, or any future updates whatsoever. At least by official means. The phone was launched in November 2012 and remained on sale for only six months (until April 2013), before the Un-carrier withdrew it and made the Lumia 521 and 921 its only Windows Phone offerings.
As of now, the Lumia 810 is listed in Nokia's software update pages as a phone that won't be receiving the Lumia Black update, which contains Windows Phone 8 GDR 3 and Nokia goodies. Furthermore, an 810 owner on Reddit shared an email sent by T-Mobile's support, in which the carrier confirms that the presumption is “accurate” and "it will not be providing updates for the Lumia 810". The message adds that "this is a normal part of a handset's life-cycle, and in this case, it's unavoidable." Well that will surely calm customers.
There is a glimmer of hope, however, and it comes straight from Stephen Elop, of all people. The same Reddit user sent the former, and still controversial Nokia CEO an email (to his Nokia email address, go figure!) asking him if he could find a way for Nokia to provide the Lumia Black firmware update for users to flash themselves. The former Nokia CEO apologized and said that he will “ask his team to assist”. Talk about customer support!
Indeed, Microsoft had previously said that all Windows Phone 8 handsets will be eligible for the Lumia Black update, but the distribution relies solely on approval by carriers and manufacturers. And another 810-owning Reddit user posted that he's "glad that the developer preview allowed him to get GDR3", which means the Lumia 810 is eligible as well. However, another user explained that developers only get GDR3, with the rest of the Lumia Black update out of their reach.
If that's really the case, and Microsoft is able to deliver an update, T-Mo's decision to cut their year-old phone's life-cycle short is questionable, no matter what kindly-worded explanation its marketing team can come up with. Perhaps the Reddit user should ask the always-outspoken T-Mobile CEO, John Legere, what's up with the Lumia 810.