I don't think a big enough deal is being made of the Icon not getting updated. There is literally no difference between the 930, the Icon, and aside from the screen size, the 1520.
{It looks like I can't post links yet but if you go to Phone Arena you can compare specs between these three phones.}
But performance-wise, these phones will all produce the same exact user experience when equipped with the same OS. Microsoft's statement about why certain phones won't be updated to W10M is reasonable enough, but it doesn't apply to the case of the Icon. Indistinguishable is correct...there's more to this than meets the eye. My guess is that the Verizon factor has come into play. Whether or not that means the Icon will never see the update remains to be seen.
The only hope I've seen so far was a reply to a tweet yesterday from Gabe Aul when asked about the Icon. His response was "not currently supported". Of course, this is as non-committal of a response as you will ever see, but I'm hoping what it means is that they are still working with Verizon to get the update pushed out but currently, as of the time of that tweet, there isn't an upgrade to W10M available for the Icon. Probably stupid of me to be so hopeful.
The Icon has got to be the most mistreated flagship of all time. If you assume that W10M will never officially hit the Icon, then it's fair to say that half of it's useful life was wasted away on WP8 while Verizon never pushed Cyan to it and we had to wait for Denim. Remember that the 930 shipped with Cyan. And of course now it's looking like we'll never see W10M. Honestly, some of the worst treated Android phones I've used have seen more updates than the single one this flagship Icon has gotten. And this phone only just passed the two-year old mark last month.
Regardless as to whether or not Verizon or Microsoft is making the final call here, it makes me really uneasy about pursuing an upgrade path in the Microsoft ecosystem in the future should the Icon be left out in the dark here. Who's to say that AT&T or other carriers, for that matter, won't fall from Microsoft's good graces and devices under those carriers won't suffer the same fate in the future? I really like Windows but it looks like I have a tough decision to make when I'm due for an upgrade.