This is what you can see on the EASA homepage in their Brexit FAQs: I am a holder of a UK issued ATPL and would like to convert that license into a license from an EASA Member State. How should I proceed?
From January 01, 2021, your UK issued ATPL license is no longer valid to operate an aircraft registered in an EASA Member State. Unless you were able to transfer that license to an EASA Member State before that date, you will need to convert it into an EU license in accordance with Commission Delegated Regulation (EU) No 2020/723. You can apply for that conversion to any of the EASA Member State competent authorities.
The description of that Regulation is:
Commission Delegated Regulation (EU) 2020/723 of 4 March 2020 laying down detailed rules with regard to the acceptance of third-country certification of pilots and amending Regulation (EU) No 1178/2011
Therefore it appears that no agreement has been found. Which is not really surprising that all of the 19 committees contained in the TCA have not been working until May 1st, as the UK was not willing to convene any of them as long as the EU had not ratified the TCA. There might be some work in one of those committees about that issue, but i see no real enthusiasm on the EU side in that regard as long as the UK is still not applying the TCA and the WA in full, see the arguments about the NI Protocol (WA) and cutting Jerseys electricity supply off (TCA).