I think that's a bit misplaced. BA arranged for a Coat of Arms from the College of Arms back in the early 1970s, as many UK companies do - all the banks, local authorities, sports clubs. It's not a terribly exclusive club, dob the Heralds £18k (or £6K if a citizen) and a coat of arms will ensue. I vaguely recall that Air Canada has a coat of arms too, for the Heralds the sun still doesn't set, though I may be mistaken on that one.

The BA one has been modernised, but it's been on BA's aircraft a long time. I don't imagine many Brits - in so far as they consider these things - would think BA has a royal warrant, any more than the London Borough of Newham has a royal warrant. Both have coats of arms.