I feel like Boards is overreacting to Eve nerfs.
She's not really under powered imo, it's just that having better team coordination allows the team to maximize her strength of early map pressure, hence why she was a semi-popular jungler in the LCS. Eve has no CC when ganking pre-6, so you would need your laner to coordinate with you more in order to pull of a successful gank.
The nerf hurts a bit, but let's be real it's not going to gut Evelynn completely due to the fact that she has passive mana regen while in stealth and she has almost no mana problems once she gets Runeglaive.