If Andre Onana comes that is a different story, but Manchester United is not all set if they start into the new season with only young goalkeepers. I guess that is why they stl keep the option with De Gea as some kind of joker. But De Gea won't play that game for very long and I assume he will make Manchester United bleed hard financially if they have to decide and offer him another new contract. He won't sign a contract below his expectations.
Over reliance on Degea almost gave Teng Erik a hypertension when he thought of making it among the top 4 was squashing out right in front of his eyes, it took lots of combine effort and extra calculations before they got to that spot again and he doesn't want to repeat this mistakes again, he is taking his chances to source for another good goalkeeper and as Onana is available in the market, they are putting extra effort to bring him to Manchester United but De Gea unofficial announcement and what to expect in the future is not available, the club and him are not saying anything and that is why people think they Manchester United may still need De Gea.