If I don't complete this and act 3, will I not have a chance to get the winning outfit next year? The confusing mission system and the fact that I STILL have to do these missions despite already having all the rewards for part 2 is not a form of good game design

Marvel Rivals is a Super Hero Team-Based PVP Shooter! Assemble an all-star Marvel squad, devise countless strategies by combining powers to form unique Team-Up skills and fight in destructible, ever-changing battlefields across the continually evolving Marvel universe!