"What is a concern is if someone contacted Microsoft with an issue that is on an unsupported system - Microsoft will simply not support it and therefore not help"
I have news for you - having a "supported system", even paying for support is no guarantee with Microsoft you will get any. At least not what any normal IT person would class as "support".
I have an outstanding issue with Microsoft with their Outlook.com service (the subscription "Premium" or "add free" as it used to be called,service NOT the free one) and the support with the issue on that has been APPALLING!
It was worse than amateurish. It was utterly childish.
I've had to escalate it TWICE by firefiring off emails to Nedella, plus the PR contacts in the US and UK to get anything to happen. The first time nothing concrete happened, despite promises when it was supposed to be in the hands of someone senior at Redmond, and then summarily closed without explanation.
The second time got further and raised with the "Engineering teams" who, without any testing, came back (via an "escalation manager") saying "It's all fixed."
Bollocks was it fixed! How the hell can anyone serious in IT claim a problem is fixed without ANY form of testing to verify it.
It has currently been re-opened again after I fired off shed loads of evidence showing that they may well have fixed "A problem", but what ever that was they had NOT fixed THE problem.
Plus a comment to the effect of "A problem is not FIXED until the customer has tested it and verified it is fixed".