A small piece here quoting Pierre Fillon saying they've only received a 'couple of hundred' requests for ticket refunds.
https://www.motorsport-total.com/24-...ket-erstattung
Make of that what you will. I assume most ticket agents have held on to their allocations in hope of re-selling them.
I guess you'd be ill-advised to buy a ticket currently if you didn't already have one. But if it does get cancelled they may well roll it into the 2021 event. Not sure.