Regarding airbridges, my understanding is that a lot of airports charge for the privilege so if there is a choice between an airbridge and a non-airbridge many airlines will choose l the latter especially the locos. I have had the experience of non-airbridge departures and arrivals at both Heathrow and Gatwick in recent years.
I would not get too upset about Atlas, you only have to look at the extra flights of Blueair and Wizz recently announced which will more than compensate for there loss.