Well, I don't know why you want something "old" French here.
When I said "champagne is not old French", I meant is not only old French. It is current French, that's what I meant, so no need to say "champagne is old French", just say "champagne is French". Imagine if I say, "York" is old English.
The wiki you mention explains all that very well:
Borrowed from French champagne (“sparkling wine from the Champagne region”), from Champagne (“region and former province of France”)
Well, I don't know why you want something "old" French here.
When I said "champagne is not old French", I meant is not only old French. It is current French, that's what I meant, so no need to say "champagne is old French", just say "champagne is French". Imagine if I say, "York" is old English.
The wiki you mention explains all that very well: Borrowed from French champagne (“sparkling wine from the Champagne region”), from Champagne (“region and former province of France”)
https://en.wiktionary.org/wiki/champagne