It's hard to disagree that evelynn has gotten stronger. Pink wards were a form of counterplay and they have been rebalanced in a way that makes them less reliable in their capacity to prevent eve ganks. Is she so strong that she's toxic (lacks counterplay)? That's harder to say.
You're still able to put green wards on her camps so you at least have a foggy sense for where she is (similar to season 3), and it's not completely unreasonable to push your lane (I speak only for bot lane) enough to defend at least a vision ward in the river/riverbrush. If you're losing lane and can't push up, is eve really able to gank you anyway? Her lack of hard CC almost requires that she ganks you when you're further out than if she were J4 or something.
With that said - I've been banning her every game O=)