If that is true, then that should've been the video, with proper evidence that with build that is reachable with reasonable amount of effort, one can deal damage comparable to Ziggs' mechanic. But If we are going to consider any Mage with 1k AP build, then Ezreal is not as much of a problem considering how much on-hit magic damage the Mage will be doing with basic attacks anyway.
I'm not saying Ezreal will be balanced on release, but using Vandril's videos as evidence of disbalance is futile majority of times as he mostly focuses on intentionally over-the-board builds and scenarios just for keks. He managed to get negative amount of HP on Vlad If I recall well, too, lol.
Also I am not usually fan of removal of Gameplay posts, but jumping to favoritism not giving the slightest look to the title of the video, Ezreal's items or his AP is exactly the type of shitposting which created the Bigfoot legend and many headaches.