What if by 'removing' they mean to replace with something better. Like Fight Pit gets replaced with a King of the Hill mode where it's easier to defend but gets harder to hold the top spots.
Maybe they started adding weekly war mods to fight pit or pit cuts all rune bonuses in half.
Or expedition becomes cage match and only lets you use each hero once.
Crypt could become War and the defensive lines are picked from the enemy's Coliseum defenses.
I can't see them eliminating any of the game screens, they don't seem to have the skill. However, they could repurpose them in ways that aren't mind numbingly boring (war, Crypt, expedition) or filled to the gills with identical teams (fight pit).