Originally Posted by ISTFlyer

Flights may be zeroed at the moment but until you get a cancellation notice ( by e-mail, phone, or when you log in to MMB ), you wouldn't able to get a refund.
To avoid overcrowding at hotlines at the same moment, BA is gradually sending cancellation notices to each passenger.

And, yes all LHR-NCL flights are zeroed for June so you should receive a cancellation notice soon.