De Gea is getting old and maybe that's why Manchester United tried to decrease his salary for the next season since is a famous payer and achieved many goals for this team. It was not good to ask this from De Gea however I think it was not about salary but that's mostly because of Ten Hag, he prefers to work with the goalkeeper he had at Ajax
De Gea has being keeping brilliantly well for Manchester United over the years he has been with the club but the club decide to reduce his pay starting from next season which I think he wasn’t expecting such from a team he has supported and played for over the years and achieved a lot for the team. There’s no doubt that his performance has reduced drastically from the way it use to before, but the team do not feel the need to come direct to him that they don’t longer needs his service at the club but rather try to send him away by reducing his salary. I don’t bales the both parties for anything they decide at this point. If he no longer fit into their game plan, he should carry on with his career somewhere that’ll be better for him than staying back.