There are still a lot of use cases for solid on-premises OS deployments on physical, local machines. They're not mainstream anymore
I think you can be more strong on this point. The reality is that this *is* the mainstream. 'The Cloud' work is important, but more than important, the people doing it are *louder* than everyone else and the media coverage high since it is novel, but mainstream is remarkably little changed over the last several years.
RTM did mean that all the showstopper bugs were taken care of, and the concept of "ship it, we'll patch it later" just didn't work. All I do know is this -- Microsoft is toast if Grandma can't upgrade her Windows 7 box she bought at Best Buy with zero issues.
That is the facet I find concerning, 'RTM is no big deal' statement is bad because it *should* be a big deal.
Maybe they can juggle LTS and non-LTS effectively, but they have every risk of getting too caught up in the enthusiast perspective and pissing off a lot of their users. I know a fair number of people pissed that their google apps change drastically on a whim on their phones, and it seems MS may jump to that model. That said, the pissed off users don't really have anywhere to go. The developers rule the roost nowadays and all companies are enabling new and shiny and changing and no one is being pushed to drive for a stable experience.