I only tested during the first week, though I don't think they mentioned changing Flying Blade, only the base skill and Shrouded Daggers, but IMO, no.
Even though it's off the GCD, the dagger still has a travel time which gives it a delay of about a second, depending on the range. Even close up, like about 8-10 meters from a target, it's kinda clunky in that you need to wait a bit before you hit it a second time to teleport, and any further gets worse.
I haven't tested Shrouded Daggers, both before and after this latest PTS patch, but at the least, Flying Blade is now a dead skill, IMO.
It's exactly the same as NB's ambush, except you need to hit someone first with the dagger.
It's ok enough for classes that don't have a reliable gap closer like sorcs or necros and dont want to slot s&b or 2h just for that.
I actually found it didn't feel that bad, the mark lasts for 5s and the gap closer/initial hit does about 66% of a single target spammable?
What I found to work the best:
Light Attack - Flying Blade
Light Attack - Skill - Gap Close
You can do this, but it feels less fluid because of the travel time on the dagger:
Light Attack - Flying Blade - Gap Close - Skill
The Gap Closer has a short animation that blocks off all ability use, even in melee range of about 0.7s so even though it doesn't fall within the GCD, the delay is noticeable enough to feel like a GCD. With the first option I mentioned. You can animation cancel a skill like hurricane in to the gap closer. I'm sure every class has something they could use there.
I didn't like it at first it seemed clunky but after testing you can cast then use a ranged skill and since off the GCD gap close and ulti or other skill all at the same time its fun, so I do like it now, its just different. You know how ESO players feel about different..