Don't be ridiculous.
https://dotabuff.com/heroes/winning
She was middle of the pack before her buffs - why would she suddenly start winning the majority of her games? Since we are reasonable people I hope we can agree that a hero who is expected to win more often than it loses is imbalanced. Even a 55% expected win rate results in a hero being picked/banned every single game, obviously, a hero who wins more than it loses is one you want on your team.
What makes Drow game breaking is she's impossible to stop now. I've gone mid against her as Invoker and started killing her with cold snap/sun strike as early as level 4. Get her 0-3 before she even hits 6, but once she does, game's over. She retreats to the jungle or gets a support to watch her in her lane (yes, even in mid). She doesn't need levels, she just needs items. And you can't, CAN'T stop her from last hitting when she turns 6. If you stack the lane severely against her, her team can just ward up and she can jungle forever with as little as a mask of death. Even if she was feeding her lane she will emerge at 25 minutes with an item, same farm any other carry would have in a lane that was actually even and she lost horribly. Give her another 20 minutes and she has BKB manta buriza you've lost. Once she hits 16 with those items she's spitting out 1k crits on people with 1600 health and her insane inherent agility gives her all the attack speed she will ever need.
Pick Drow in a fair game and you will win more than you lose, she is broken right now. They did fix her global aura, whether or not that changes her win rate (doubt it but we'll see) can shape our opinions in the future.