The Windows 10 market share is still much lower than Win 7, as you can see here:
I reverted to Win 8.1 when I discovered that I could not install some crucial legacy software on Win 10. I have no plans to upgrade to Win 10, ever. And I’m not alone.
So if Steinberg wants to make use of some new win 10 feature, they’ll have to continue supporting win 7 and 8, or lose customers.
The undeniable fact is, Sonar can detect hotplugged USB interfaces – in Windows 8.1. Steinberg has no excuse. They need to catch up.