With a slot waiver in place until the end of March, meaning that airlines are at no risk of losing their slots by not flying, some other carriers are taking the opportunity to test the Heathrow water.
Romanian low cost carrier Blue Air is not your typical Heathrow carrier. From 1st December, however, it is switching its 5x weekly service to Bucharest from London Luton Airport.
More interestingly, the service will expand to 11x weekly from March 2021. This presumably means that the airline has been able to borrow some Heathrow slots from another carrier which has no intention of operating them next Summer.
Blue Air has, reportedly, also requested slots to move its Cluj service from Luton to Heathrow.
You can find out more on the Blue Air website.