The reason Miguel is doing everything in this movie is to make sure the Spider-Canon stays intact. It’s the basis for everything, such as trying to keep Miles from going home and saving his dad. Miguel is sure if that happens, the universe will end.
But, at the end of the film, when Gwen’s dad says he quit his job and is no longer captain, Gwen says “But that means…” and trails off. In her mind, at least, that was the canon changing without significant consequence. We don’t see what happens in Gwen’s universe after that, nor do we know another Captain she loves won’t die in the future, but it’s the movie’s biggest clue that, yes, Miles can save his dad and the universe at the same time.
