I have a few LHR-JFK trips in April and May. I've been hoping for cancellations as I don't want any more vouchers.
I got lucky with one in April but another April reservation was annoyingly on the two daily flights that seem to have been kept running. It seems that they have cut the service right back to two a day all through April but left the May onwards flights in place for now. I am hoping there will be another block cancellation coming up soon.