I'd also take issue that EDI is well served with connections to Canada especially YYZ or that fares to there are dirt cheap. On a trip there back in May it was much cheaper to fly EDI-LHR-YYZ than comparative fares on Air Canada Rouge. (There were no direct flights from GLA on the days I needed to travel so that wasn't an option).
I would say, despite the plethora of rumours there may or may not be around route development at Edinburgh, that at the very least another competitor or a year round service on the EDI-YYZ route would probably be extremely sensible and workable.
GLA used to do well with Canadian routes but Calgary and Vancouver were chopped about 2/3 years ago. I wouldn't be surprised if their options to YYZ go backwards as well. EDI would just generally be a much better option.