You could look here:
https://www.royalmail.com/sending
Many airlines are cutting back passenger flights, since the planes were close to empty anyway.
But that doesn't stop shipping.
While most passenger flights also carry goods, there is no reason to be concerned that your purchase will be unduly delayed.
EBay gave you a window for delivery. Mark the last date on your calendar and relax. When the last day approaches with no delivery you can come back to this thread and enquire about your next step.