The Aer Lingus story in my opinion is a non-story...
If you choose to travel at the moment, you are basically choosing to take the risk of being unable to social distance. Aer Lingus are the only airline operating between London and Belfast, and it’s inevitable the few seats being made available will sell out.
Looking at the Aer Lingus website many days they are sold out and charging a very handsome price on other days!
Its exactly the same with Wizz Air, you can cross your fingers for an empty flight and hope most people are not travelling, but if the flights full, tough!