I think the article misses the point of "Universal" and of the linked suggestion
Microsoft has stated that Windows 10 is the final version of Windows, that any subsequent versions will be updates to the 10 platform. Therefore the "universal" semantic is appropriate because 10 is the not only long-term but permanent Windows platform for the company. Meanwhile, iOS and Android code compatibility (though not binary compatibility) is coming via the "Bridges" APIs, https://dev.windows.com/en-us/bridges