So you think it’s a good idea that Steinberg will get someone to load up the finished version on Win 7 and write out a list for the community to say what works and what doesn’t? …Based on one machine/one user?
Firstly, what use is that to anyone right now?, and secondly, why would they do it when they’ve already said they’re not supporting Win 7? The Resources and costs come in to play when they’re actively checking Win 7 compatibility across multiple machines and workflows, and feeding that back into the development of C10.5 onwards. A professional company would have to operate in that way if they put out any kind of notification regarding Win 7 - but they’re not supporting it, so totally nullified.
‘If’ C10.5 runs on Win 7 then the community is far better placed to carry out such testing and report to other users, Steinberg have supported Win 7 since V5, and they specifically designed v6 with Win 7 (64bit) in mind and added VST 3.5, C10.5 is going to be the same kind of move where Win 10 is the primary focus. What matters most is here is what they can utilise going forwards, and shed the skin of a 10 year old OS.
A large number of people still use Win7, not everyone will be able to transfer over right away
Yes they can, large majority of users can easily move to Win10.
They’ve had many years to do so already, and C10 isn’t going to magically break if they decide to take another 12/24 months to upgrade either. Why should their be a sudden immediate panic to ‘transfer over right away’ after sitting dormant on a 10 year old OS anyway?
Which actually means a potential loss in sales.
Improving a product and updating it to the latest technology will have the opposite effect, would you rather see a C10.5 that runs slicker and offers new features? Or just continue supporting Win 7 which obstructs that path?
Besides, they have beta testers, beta testers who run Win7, so I know it was tested. It was tested. As -Steve- pointed out, some things definitely will not work for Win7… which means… it was tested. > 
But you’re asking for them to specifically tell you of new features and what is and isn’t working with them, and you’re not going to get that for the reasons i’ve pointed out.
The product hasn’t even been finalised yet - so again, what’s the point of beta testing feedback being thrown around the forums? If you want to be running C10.5 and receive support then get on Win 10 - that’s the message, can’t be any clearer.
If it’s a sneaky question so you can find out which new features are being added to C10.5, then you’ll just have to be patient.