What are you talking about mate? Transfers are announced outside of the window all of the time.
Transfers can be announced whenever the clubs want. Just because it's announced doesn't mean it's officially completed. It's very common now to see the 'pending medical' announcement. See this being no different.
Transfers are annonced when it suits both parties and the financial ramifications are set in stone. Yeah, for FdJ, it's going to take a little bit longer and it's pacing really well. This isn't some second tier player who hasn't played football in months. FdJ's 21/22 football season literally just ended less than 10 days ago. He's on holiday, but has been briefed by his agents, Barca, and United via EtH.
Barca clearly is doing the same thing with Raphinha, Lewandowski, and a whole host of their other transfers...who are free. It's just not United's POV, they are also dealing with Barca and La Liga rules that they have to meet for their purposes.