The event film is not sonic 4 part 2...most likely a shadow movie.
Many people in the industry have said event film mostly can mean a film that's not a numerical sequel to the previous movie.
The knuckles show was called an event something for example.
Maybe they introduce Abraham tower as the new gun commander.
How they will introduce rouge and omega along with black doom is complicated.
Sonic 2 introduced tails and knuckles only. Not the main villain too.
I can see rouge working for gun already. Omega is harder because we do not know if Jim Carrey's last movie is movie 4 or 5. So his primary goal of taking out the doctor is kinda on ice.
He could want to destroy all eggman robots and helps shadow and rouge because the black arms would get in his way.
What are you guys' thoughts