Chelsea are said to be ready to sign Frenkie de Jong and Aubameyang both now. However it depends on whether Barcelona are thinking of letting them go now. Actually Barcelona are in a troubling situation when it comes to the La Liga. They will need to cut the total salary of the players somehow otherwise they might face a problem like they wouldn't be able to register some players as you know. So I wonder if they will go for selling at least one of these two players to relieve a little.
Barcelona will definitely release their players if they don't want to be caught in sanctions. But there is no certainty who the players will be released. Aubameyang will not be released because he was bought from Arsenal by Xavi Hernandez. Frenkie De Jong has the opportunity to be released to Chelsea because Barcelona are still holding out a deal with Manchester United for the De Jong process.