It should be adjusted accordingly, however.
I don't think Eve's kit is weak. I just think too much of her power budget is tied up in her ultimate. What's that? Broad, AoE execute with untargetability frames and a long escape afterwards? Sure, if she mistimes it she'll gimp herself for the follow-up, but its still an enormously powerful ultimate.
New Eve feels unsatisfying - sure. But people aren't yet realizing that she still has her perma-stealth. Riot locked it behind level 6 because they gave her hard CC and %damage. Rengar is infuriating enough with a gapcloser from stealth, and he hasn't got hard CC along with that unless he uses an empowered root, which lowers his initial damage output. Eve can't have a powerful ult, her stealth, as well as a gapcloser that CCs you from said stealth without a few balance levers. That's just getting back to what made her unhealthy and in need of a VGU in the first place - no counterplay from stealth.
If you want to lower the CD on her ult, give her a longer E, and a more responsive W (all perfectly valid ideas), then you'll need to take away her untargetability. Or the MR shred. Something. Currently Eve has a kit with a lot of really potent strength, they just don't blend terribly well together. Buffing her potency straight up and/or removing the levers that make her more fair to play against is just asking for trouble.