++ the future of Microsoft Lumia mobile phones ++

+  you have to pay attention, there are still fans of the Lumia line inside Microsoft (just to be there, they have sold in this year some Lumias testing the fan base). There are chances that the Lumia 950s could run full Windows 10 OS at least until 2025, the problem is with the smaller capacity devices & the Windows 10 mobile platform & avoiding a KO on the OS market (after desktops and laptops, now the phones are representing an important share of computing devices) // it would be the beginning of the end for the OS division (future technologies may reduce the importance of desktops) // I have compared the situation with the Mercedes F1 Team, because in 2012 they have been at the bottom of the pack // in the last part of the season only Schumacher had obtained a 7th place in Brazil under rainy conditions & no points for Rosberg // but with perseverance better days have come for the Team //

There is no miracle happening. As far as I am concerned the Lumia line was obsolete a long time ago. Phone production was discontinued in 2016, software development officially killed 6 months ago - can you get more obsolete than that ?

so, barring some miracle, like a white knight on a steed riding in to resurrect the support system for win 10 mobile,  the lumia line of phone will be pretty much obsolete end of 2019. even the 950xl line which actually has a replaceable battery.

• an A- for this great answer (Samsung 7s reminded me some F1 cars in the 90s & after such problems they are proudly developing// & Apple has to thank for Microsoft for its success, i.e. they have received software support in critical years &  // I have seen a report on WSJ about the manufacturing process of Iphones in China & workers deserve better conditions // )
• windows phone 8.1 phones & windows 10 mobile 1511 still work as phones & can access the Windows Store (some apps or games may not run on these devices) //

• well our pride the flagships have been launched less than 3 years ago // do not worry the platform receives mainstream support until December 10 (Human Rights Day) 2019 

Not entirely correct. Only the last Windows Mobile devices will get that period of support, for most of them it will end earlier.

Support for Windows 10 Mobile is almost the same as other editions of Windows 10, but the support duration is slightly longer. Each version of Windows 10 Mobile is supported for around 26 months (2 years and 2 months) from the date of release. End of support dates for each version of Windows 10 Mobile:

Windows 10 Mobile version 1511 build 10586 / Initial Release: January 9, 2018

Windows 10 Mobile version 1607 build 14393 / Anniversary Update: October 9, 2018

Windows 10 Mobile version 1703 build 15063 / Creators Update: June 11, 2019

Windows 10 Mobile version 1709 build 15254 / Fall Creators Update: December 10, 2019 *

* Tentative dates, support may be extended. The exact date will be announced within 1 year of these dates.

Lumia Support Lifecycle

Lumia phones are supported for 2 years from the date they are launched. This means they get Feature Updates during those 2 years. Each Feature Update is supported for around 26 months. The last Feature Update that a Lumia phone gets at the end of the 2 years will be supported for around 2 years, so the total support period for a Lumia phone is around 4 years from the date it is launched. 

In short, a Lumia phone will get Feature Updates for 2 years and it will get Cumulative Updates for the last Feature Update for 2 more years.

Please note that the support from here onwards will consist only of bug fixes and security patches - this is definitely not mainstream support - it is just MS doing the absolute minimum which is legally required. No new features or hardware will be developed further for Windows 10 Mobile. Effectively the platform is on life support in a coma from which it will not recover.

  yes we receive only fixes & this is how we become better week by week 

Yes, like the update which broke the PDF function in Edge last month so they had to fix it 5 weeks later.

Android 5, 6 receives fewer fixes I can bet on that 

Yep, because they don't need fixes, just security patches - not bad for OS released in November 2014 and October 2015 respectively.

we are getting faster, not like some IPhone models // 

That's Apple slowing them down on purpose with specifically designed software updates which perform exactly as desired, not by botched updates like Microsoft.