If you had no concerns running a pirated copy of the old version what's stopping you from getting a pirated copy of the newer version?

Well, a legal copy is always better than a pirated one. The least of the benefits would be the lack of need to unlock it.

But I guess he/she asked the questions because Microsoft might have indicated that in the past.

The update isn't available for people with group licenses (i.e. schools, large workplaces).

So, no.

Not even "personal" MSDN(AA) licenses.

Are you sure about this? I have this kind of license (for Win 8.1) and in the "Win 10 upgrade window" it said that my machine can be upgraded. Although, I have not tried it, yet.

That only means that systems activated by pirated KMS servers will not get an update.

The real question is what happens with systems with pirated OEM certificates in motherboard firmware. IIRC this was the most reliable method of piracy for Windows 7.

I believe you can but the upgraded version will still show as non genuine.