"template" is not considered a separate file in AutoCAD: it's an OS level lock that the T in the file extension provides to the file. AutoCAD will never override an OS file lock, what you wish for will never happen, Microsoft will not allow it, not sure Apple is any more flexible if the same rules apply there.

Yes, 2017 for MAC was late this year, it wasn't in the years before, doesn't change the reality they are on separate schedules and because of that they are separate formats.

I doubt anything will change until a 2018-for-mac comes out when it does, again, it's been the reality for many years on the MAC side. I hope the twitter folks did not give you the impression they can alter product release times in any way by passing your note to the "devs'.