Sony has not been that fair to change the rules a few days before SFX launch. I think a number of Sony higher-ups may have entered Panic Mode Level 1 when they found out that people going to flash SailfishX are way more than a dozen nerds. While this does not rule out their Insane Fear of Dem HaxX0rz Compromising Our Boot Keys, and does not rule out other scenarios, their will to get back in control of flashing (mandating the Windows Emma tool) could suggest they're readying some unofficial support (an "approved SFOS image" that may get flashed by an "approved service center" using the only "approved (Windows) tool").

Emma prerequisites are somewhat annoying - not only you need Windows 7 or later (sadly Windows XP is not there: have you some recent Windows PC hanging around? will Emma work in a VirtualBox window? will it safely operate under Wine?), but you also need to register a login and have internet access (which could possibly be used to block "unofficial" - aka community - releases). Yet, with the exception of userfriendliness for illiterate people scared by the "Linux" word, it's not clear if Emma actually gives some benefit if compared to the straightforward Linux script used till now by Jolla guys themselves.