This would lead to a forked Android?

This is all based on a warped reality understanding. With or without an agenda.

So the user base use older versions now than they did when Android was in 1.6. That's not only expected, it's the normal use case. Hardly anyone have ever had an fresh OS version on their Windows Mobile, Symbian, Series 40, or any other phone, beyond the first month in sale. Heck, the same goes for PCs and microwaves, too. Nokias Windows Phone 7 won't be upgradeable to Windows 8 either.

Android and other upgradeable cell phone platforms are improvements on the standard use case, not lagging behind.

Even if it took a year from new version till phone production, hardly anyone use phones older than two years. Google knows this and plans accordingly. Cell phone builders thrive in this and base their sale expectancies on it.

Google, IOS and other upgradeable OS's are all way better on upgrades than ANYTHING was prior to the cell phone OS revolution.

Edit: hopefully somewhat better grammar.