Perhaps, but that still leaves the balancing issue of Ivern's ability to create bushes anywhere, and the fact that going out of vision (like in a bush) interrupts casts and AAs. And since Eve has stealth, being able to earn it just going into a bush would cripple counterplay against her.
At least with Teemo's stealth he's stuck in the bush if he wants to stay invisible, but Eve can be invisible outside of bushes, so giving her a reset essentially just by going into a bush would be too much.
I think something similar to Noc's ult would work. High CD and single target only or group target if they are hit with it (like her current ult radius). Example: Eve's ult makes her "invisible" to the enemies she "envelopes in shadows". Since that would fit her lore of being able to disappear instantly into the shadows. Just an idea though.