I decided to try again. First call to Cox, I got a "gee probably" answer, despite pushing for an exact answer as to if this upgrade is now mandatory.
Decided to call again and got a better rep who actually tried to find the answer which was it's not mandatory until Feb 2019. The tech person she was talking to did find some odd stuff on my line (like it looks like it's off the hook) and he'd call me directly on my cell immediately to let me know what he was seeing.
That was more than an hour ago .Sigh.
And then this company wonders why they have such a horrible customer service reputation? :-0