It wouldn't be the first time. Hawkeye died in the first story, but that didn't prevent them from making a "Old Man Hawkeye" series, which was a prequel (it was about Hawkeye killing the Thunderbolts one by one for their betrayal during the day the heroes fell, before he goes completely blind). Or remember Sin City: Marv died in the first story, but as he was a cool character they kept using him in prequel stories and "meanwhile" stories.
One thing I dislike is the names. Why the codenames? Why not follow the example of the initial comic, and name the comics "Old Man Clint", "Old Man Quill" and "Old Woman Romanov"?