It is important to make a distinction here between “Insiders”, those who will be receiving the latest Windows Mobile 10 builds through Phone Insider app and normal users who won’t take the “Insiders” route and are assumed by some to get stuck at Lumia Denim update. We got some questions on whether there will be any update for normal users before Windows Mobile 10 and post Lumia Denim.
So, what we understand here is that Microsoft will anyway push compatibility and stability updates mostly without major changes to normal devices post Lumia Denim so that when Windows Mobile 10 finally rolls out, it goes without issues. So, it is wrong to assume that normal users will have to go for “8 months” without an update. Normal users will sill receive updates post Lumia Denim though, this is another question whether Microsoft wishes to call it Windows Phone 8.1 GDR2 update or not. Some of GDR2’s tipped changes like “Mobile Data Toggle” and Cortana for more already arrived with GDR1 version 8.10.14219.314, so even if Microsoft releases a GDR2 update, it will be a watered down GDR2.
Life for “Phone Insiders” is going to be much more dynamic though with lots of new builds and feedback to be given.