Something along the lines of "We officially support development with ASP.NET, .NET Core, Mono, etc. on Microsoft Linux for deployment to Azure Microsoft Linux instances".
What you're describing will never happen. MS wants to keep .NET/etc development easiest on Windows. They have no incentive or plans to deliver the same support for developers on Linux as they do for devs on Windows.
Any true "linux distro" released by MS will have gimped out tools. If they ship windows with a Linux ABI ("Ubuntu + Windows") so you have MS support, then it's never going to be proper Linux.
I don't see how anything MS is doing really helps Linux. If they were really pro-Linux they'd make a commitment to supporting it 100% by making 100% of their development software compatible with Linux.
Just more extending for the purpose of extinguishing. I have no reason to believe otherwise because MS has not inspired confidence in me. All the tools they've open sourced or released on Linux are half assed. A billion dollar company like MS can make good software for Linux that isn't gimped, they just choose not to do so because they prefer that Windows remains a more viable platform for people who use their tools.
However there are businesses out there who like to work in a single vendor system as much as they can. I have no doubt that Microsoft will come out with their own Linux distro in the next 2-3 years. They don't need too, but they also didn't need to do lots of the things they have done recently.
I feel like I've accidentally stumbled upon some internal discussion group of Microsoft's where very low level employees who completely misunderstand the market give their Microsoft-centric view of the world.
I am assuming you believe Microsoft will not be venturing into the world of building their own Linux distribution?