I fully support Steinberg on this one!
Just a reminder that Windows 7 is EOL n January 2020, which means even Microsoft won’t be supporting it. If you run Windows 7 connected to the internet any time after January 2020, you are at risk of any number of vulnerabilities that appear but don’t get patched. No one is forcing anyone to upgrade to 10.5 so at least you know that you can always use Cubase 10 on W7 until you upgrade (which should be January 2020 at the very latest).
Windows 8.1 while a decent OS truly is a beta for Windows 10, and a bad one at that (from a design standpoint). If you check out adoption charts of Windows 8.1, you’ll see how few people use it compared to W7 and W10.
I’m all for Steinberg focusing on less OSs and spending time getting more Cubase rock solid and awesome for us.
Oh and one final point, Cubase SX 3.1.1 is not officially supported on Windows 10 but it works perfectly. If you’re so determined to run Windows 7, I have a feeling Cubase 10.5+ will still work on it (due to Microsoft’s pretty strong continuity of their SDKs); but you can’t expect Steinberg to support an OS that’s no longer supported by the OS vendor.