It will happen. The question is whether CO take advantage of an early departure from Scotland to attract the front end traffic.
This would mean the first Scottish departure would get a businessman in New York in time for a full day's business and probably get in ahead of Concorde in NYC.
A 7.00 from Glasgow and a 12.00 noon from EDI
would make more sense that having departures at approximately the same time from two airports 50 miles apart.
If the BA/AA thingy goes ahead as seems likely what is unlikely is BA return to the GLA/JFK service specially if CO are double daily out of Scotland.