Riot, the Nerfs to AP itemization basically undid ALL of the itemization changes in the AP item update several patches ago.
AP champs had their power spikes reduced for when they occured because it took too long to reach, while also standardizing AP amounts across the board.
This is what SHOULD have happened for preseason.
AP Costs Go down, AP amounts go down, AP ratios go up by .2 across the board to accomidate teh lower AP from items.
Slamurai Jack1 votesAP Mages win rates are at an all time high and nearly every mage had their winrate go up this patch. Check out champion.gg if you don't believe me.
CrazedPorcupine2 votesThe only AP mages whose winrates went up are the utility mages that had high bases and decent scalings.
Brand, Lulu, Oriana, Anivia, Annie, etc. All went up because of their high base damages and utility allows them to function well with lower AP/less items than other late game mages like Veigar (whose winrate plummeted down to around 44%)
AP mages that rely on late game/multiple items to carry have seen their winrates drop.