No, their plan has never been to offer De Gea a new contract, but it all depended on whether they can find a new goalkeeper and that was an open secret. As soon as they successfully found an alternative for De Gea, they refrained from negotiating any further with him and that was expected by everyone. The goal was to sign a much younger goalkeeper who can actually still develop and get better and who is less prone to fatal mistakes during the game like De Gea had them more and more often in the last few years.
Onana's arrival at Manchester United is inevitable and it's only a matter of time before he joins the team. Once MU finishes a few remaining steps, they will be able to make an official announcement regarding his signing as a new player in the club. No reason for de gea to get a huge salary in manchester united.
His performance last season was very disappointed. It's now time for MU to move on from him. Onana potentially play even better compared with de gea. The club needs regeneration and it's a must.
There's is also another important task to remove meguire from the club as soon as possible. MU for a better team next season.