In what world does Riot think that Annie needs mobility? Annie is supposed to be the answer to a high mobility creep. The fact that she *"needs"* mobility speaks volumes of the state of mobility creep, damage creep, and just overall game balance in general. Annie lacks mobility so she should make up for it with amazing burst and good CC. Annie has always been balanced around flash, and for a brief time was really good with ghost.
Believe it or not, there's an entire class of champions like Annie. They're called mages. Mages do (and should) lack mobility. What mages lack for in mobility they should make up for in other parts of their kit, like wave clear. Even on the League of Legends Wiki it states:
"Mages are champions who typically possess great reach, ability-based area of effect damage and crowd control, and who use all of these strengths in tandem with each other to trap and destroy enemies from a distance...Though mages tend to focus on killing prime targets in combat, they can also fall back to their innate crowd control and utility to manipulate key opponents, protecting their team from them or setting them up for a takedown, and in the right circumstances can damage and control multiple enemies at a time."
But apparently Riot thinks otherwise and thinks the best way to help a ***MAGE*** is to, for whatever reason, give them mobility. Annie needs help, don't get me wrong. But not like this.