I think the reason that made De Jong want to stay at Barcelona isn't that Barcelona still owes him, but because he really just wanted to play for Barcelona and he has high loyalty to Barcelona. So most likely he would be willing if his salary was cut. We all know that De Jong turned down offers from Man United and Chelsea which both teams are even willing to pay off Barcelona's arrears to him but De Jong still insists on not leaving Barcelona. I think if Barcelona had a solution to their financial crisis then they wouldn't have let De Jong go.
True, as we have known before, and to this day de jong is still wearing a barcelona costume rather than accepting an offer from manchester united or chelsea.
Regarding the salary-related issue, some news reports from both sides have agreed. negotiations between the Barcelona management and De Jong have already been held. now, both parties only need to formalize the agreement with various conditions set out in the new clause.
IMO, if referring to what you said.
I believe that De Jong's loyalty cannot be separated from Xavi's role, when the transfer saga of De Jong surfaced, Xavi was very intense in talking to De Jong. he often discusses with de jong regarding current conditions.
because xavi still needed the services of de jong, in the end de jong agreed to cut his salary and until now de jong is still wearing the barcelona costume.