Sadly as I may have mentioned before TG are not of this world.
They defy most logic that a westerner could employ.
They do not fare dump or price match per se & tend not to regard competition & certainly do not think of themselves as a holiday airline.
Most travellers to holiday Thailand really do know all the other routes to travel there & all involve a transit stop in Europe or Middle East.
Even Thai`s in the UK mainly elect for a transit nowadays rather than a more convenient direct flight with the national airline.
The hope for MAN would only be if there exists Thai political influence in the North or if they have ordered too many shiny new a/c types.
Neither being a commercial decision tho.