There never was meant to be an upgrade path from Nokia
Microsoft need to step back a bit and look at what chaos and damage they are causing to the Windows Brand. Microsoft should just admit it, there was never meant to be an upgrade path to Windows 10 for Nokia Devices.
Rearranging the deck chairs might seem a good idea, but throwing them around the room, wasn't meant to be part of the solution. (Microsoft keep using the same unloved Metro deckchairs too, and no one's willing to put their head into no-mans land, and say - 'failure')
Microsoft - Stop rushing, work methodically, get Previews out - fine, but each new added feature needs to be complete and working, not a bag of tangled wool. iOS isn't going anywhere new for a while, but iOS does make updates look like child's play compared to f'in Windows Update.