Maybe, but I doubt it from YYC. Cheap A fares result from competition. They exist on routes with LCC competition as a matter of product differentiation. They exist on routes in competition with other legacies (think DTW-MIA vs. AA). Is AC known for cheap premium fares? Does Delta care enough about competing with WestJet in YYC?

Further, we see everyday that fares are priced as origin to destination. Count the noob posts of the form xxx-yyy-zzz is cheaper than xxx-yyy!!!. I don't see your surcharge by available segment idea gaining traction as a new pricing mechanism, at least not as a time of ticketing buy-up.

If SLC-YYC were 31 miles longer and ended in the U.S.A., current Delta policy would put an F cabin on that route. Lots of routes >720 miles have single-cabin aircraft. CO alone had ten or more such routes from EWR when Delta announced the plan for F cabins on RJs on qualifying domestic routes.