Observed it in the States, and I think it is a great gesture that draws attention to a group, not simply the individual taking the offer.
And is up to the Veteran if he/she wishes to take the offer of boarding first, the privilege being there if it is wanted. Goes to convey a deep appreciation for the sacrifices given historically by a certain group of our society.
As Break Right said....wonderful...
As to QF response...I was a First Responder for some time...never ever thought myself in the same league as a Veteran, and most First Responders I interacted with would have had the same feelings.
Good on Virgin!!!