Tbh I'm betting there will be a rework some day to this degree, because Annie's kit doesn't meet today's standards of "combination play." In reality. Annie is one of those who is still "click and shoot" in a world where other champs require combos but ultimately carry harder than Annie with more damage potential.
Annie's range, speed, and heavy reliance on flash to accomplish things really puts her out of the meta.
I could imagine an age upgrade for her skills:
Q Fireball could become a rapid fire skill, dealing lower damage per hit, but still having the mana refund, and the third hit putting it on cooldown but dealing more damage (could be used to clear 3 minions in succession rather than just 1 and then risking missing the next one to an auto).
W could become a Flame Wave Armor barrier, in which 2 arms of flame extend out from Annie/Tibbers to deal periodic damage over 4-6 seconds, with a range of perhaps 450. Could apply a burning debuff (possible setup for a rework of her passive)
E could Basically do the same thing, except stun all targets with a Burning buff for 2 seconds (creating the conditionals Riot likes at this time, and this could also apply to Brand's Burning, which would create an interesting pyro synergy).
R rework: Summons Tibbers, who picks up Annie and Charges at a specific point and knocks up targets along the way and deals damage and applies Burning. Tibbers then becomes a minion which acts similar to how the current Tibbers behaves (would be a lot more reactive for both opponents and annie allies, because her current Ult is basically unavoidable if you are already in its range, and has no counterplay)
Passive Rework: Since I'm moving the Stun onto an E conditional: Gathering Inferno: As Annie acquires takedowns, she accumulates stacks of Empowerment (whatever). At 3/8/12 stacks, Annie gets to empower 1 Basic skill permanently: Q: Annie's Third fireball does damage in a range of 350 around the target, adding damage. W: Flame Wave Armor creates three arms, and adds 5% additional damage reduction. E: Gain +150 Range. If Annie's E stuns an enemy Champion, E deals 4% + 2% per 100 AP damage to them.
Just an idea of what would be a really interesting Annie rework.