My take is they were trying to keep their powder dry in preparation for a big punishment, and so banked heavily on being able to get through this period of uncertainty with the established players being able to keep it going. While Pep has allowed players like Cancelo to leave when unhappy it is notable that both Silva and Walker have had whispers of wanting to move for several windows in a row now but having that blocked. I think they have found themselves in a situation where they realize that bet has not come off and need to retool, and while the collective transfers fees paid were considerable the profile of the players means the overall financial commitment to them isnt big.
How the Halaand extension ties into that I have no idea.