Riot, the Zed nerf makes him much more of a binary champion, something you've said you don't want.

How many times has the balance team reworked champions saying they wanted them to feel less binary? You recently reworked Ryze, Kassadin, and Veigar for this reason, to eliminate binary play styles, but their viability plummeted so fast they required almost immediate attention following their reworks (with Ryze's incoming). On these champions you took away strengths without giving them anything to compensate for that. This is basically what you're doing to Zed by removing the option to teleport back to his shadow immediately after ulting. Zed's ult was really unique because it allowed him to dodge skill shots/cc and you could really outplay you opponents if your mastery on Zed was high enough. I don't expect that this nerf really does much for his viability in bronze-low gold, but once you get higher up that 1 second he is forced to stay keeps him there long enough to be susceptible to skill shots and cc; at that point his ult is not significantly different than a Diana or an Akali ult. Sure, you can argue that he can W early to make sure that he is able to teleport to his W, but now you're forcing a Zed into a highly predictable play-style and further limiting his mobility. It is this limiting of options which is why the Zed nerf doesn't make sense with what balancing has been trying to do.

Let's look at some good examples of your balance changes: Removing DFG (as much as I miss it, playing primarily AP burst mages) forced AP carries to actually think about their builds, rather than just know they could build this one item and kill anyone. Speaking of AP mages, Sion went from being a weird AP Burst mage where he'd either stun you and blow you up with his shield, or be useless. With his rework he is now an excellent solo-laner, a solid jungler, and brings a whole lot more to the table than he used to. His ult is excellent and designed as an unstoppable engage tool. However, when in trouble many people use it to retreat. Are you going to change his ult so that he can't ult away from the direction of his enemies? No, because enemy champions can get in the way to block his retreat. But this is what you're basically doing to Zed--his enemies could previously outplay his ult, but it took skill. However, you are so concerned about Zed's ability to outplay his enemies you've inadvertently made lane match-ups which were based on skill now nearly impossible. Champions like Ahri, Syndra, and Cassiopeia (just to name a few) now require significantly less skill to outplay Zed, tilting the match-up heavily in favor of the champ holding CC, to the point where I'd be surprised if Zhonya's was even a necessary rush item for these champs when playing against Zed because his death mark is laughable when you can CC him and force him to retreat or die.

Also, why even nerf Zed? It's not like he is in the state of S2 Ahri/Morg or S3 TF/Kass where they were basically a free win. He isn't even the best option in the current tank meta. It honestly feels like someone on the balance team had a few bad matches against a Zed player and got overly salty.

TL;DR: Your balance changes on Zed confuse me because it forces him into a more binary play-style, something you actively claim to be trying to steer away from. I would like an explanation as to why you think Zed even needed this nerf, and why you think that this is a good idea, rather than just nerfing his damage.