Marvel works hard to not allow spoilers to get out and they are working on keeping the latest surprise inside of Captain Marvel a secret.
They have said that there will be a Stan Lee tribute in Captain Marvel and they have let it be known that there will not be a dry eye in the house.
There will also be another Stan Lee cameo in Avengers: Endgame. Presales for Captain Marvel are outpacing Wonder Woman, which is now surprise.