Dec 14th is a better deadline to watch. That's the date at which a state's "Certificates of Ascertainment" is due. If they miss this deadline, the electorate votes are forfeited.

Keep in mind some of these swing states don't have strong one-party control of the state legislatures, and there could be a strong appetite for a recount or closer scrutiny of the ballots.

https://crsreports.congress.gov/product/pdf/IF/IF11641