Not too sure that was the direction of the original post referred to however...It appeared to use the example of foreign airlines using/visiting SEN in the 1950`s 60`s & 70`s & none of those were actually SEN based.
That was the reference & starting point for the reply... So the visiting airlines would be? ....WZZ reducing...LOG gone...Wideroe gone (temp)
tbd...Hence the question which appeared reasonable to propose.
Perhaps another interesting posit would be why has LOG gone because of COVID anyway?...STN it`s rightful home perhaps is not a COVID free zone unfortunately.