Chris Weber made this open ended statement today on their official /Conversations blog.. So perhaps not all phones will get it - the unfortunate thing is that if its 512MB devices generally, or even just the most popular one (520), then a big chunk could be at risk. One can only hope it was just a poorly formulate statement from him or the "journalist" who wrote the story. [Can't post a link due to forum rules.. ]
Does that mean that today?s Lumia devices can be upgraded to Windows 10?
We?re making it as easy as possible to get Windows 10. Windows 10 has been designed to run well on today?s Lumia phones. Like any upgrade to a new platform, not every phone will upgrade or support all possible Windows 10 features, and certain features and experiences will require more advanced future hardware. Our goal is for the majority of the Lumia phones running Windows Phone 8 and 8.1 to join the Windows ecosystem along with an expected hundreds of millions of PCs, tablets and other devices running the next generation of Windows.