The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
-William Arthur Ward
There is a defining triangle of Tier 1 Standard decks: R/W/X Vehicles, B/G Delirium, and W/U Flash. These decks are the best and most consistent decks in Standard, and we've seen that backed up through numerous tournaments and online results. This is fact; anyone who disagrees is fooling themselves.
When a format narrows it opens up possibilities for some less consistent or powerful decks to become sneakily good. A deck with a positive matchup against one or two of the most popular decks, especially that consist of 25% or more of the field, can be a serious contender.
Various black-based Zombie decks have been a roleplayer in Standard since the printing of Eldritch Moon. The Zombie engine is alive and well, currently further smoothed out by Smugglers Copter. At least in theory, I figured that Zombies was excellent against Vehicles, solid against W/U Flash, but folds to the controlling builds of B/G Delirium. Plenty of B/G pilots are still piloting Smuggler's Copter versions, similar to Eric Froehlich's Pro Tour list which should be significantly less difficult for Zombies. All of this considered, plus the fact that I wanted to have some fun in a rare low-stakes tournament for me, I decided to give the deck a spin in a Standard Classic Event.
Black/Red versions have been on Magic Online for a while, but I decided to try out a fresher version piloted by Thiago Sapporito to a Top 16 finish at Grand Prix Santiago.
One draw to this version is the increased number of Swamps in the manabase. They allow for smoother draws with more turn one Cryptbeakers and more flexibility in madnessing a Voldaren Pariah. Extra Swamps let us play Grasp of Darkness, which is currently better positioned than Fiery Temper. Not only does it cost less without a discard outlet, but Grim Flayers, Archangel Avacyns, and 4/4 Smuggler's Copters are rampant. Grasp of Darkness gets around the protection provided by Selfless Spirit.
The other benefit of blue is Prized Amalgam. While it's not exactly what you want to be doing, it adds consistency. Prized Amalgam is a great blocker against vehicles and a solid attacker against black/green due to its eventual recursion. Prized Amalgam is an additional avenue to crew Smuggler's Copter on turn three. Hard-casting Prized Amalgam increases the frequency of emerging Distended Mindbender on turn four. This is especially important, as Distended Mindbender is your best card against B/G Delirium, your worst matchup.
In Kaladesh Standard, control decks top off with Torrential Gearhulk. W/U Flash and B/G Delirium both try to set up Archangel Avacyn and Ishkanah, Grafwidow. Both are problematic. Gideon, Ally of Zendikar is another problem card and is often very difficult to beat. Spell Shrivel and Revolutionary Rebuff both seem weak and out of place on paper, but they are hugely beneficial against problematic cards.
The last tech that Saporito had, that could by all means be played in any version of Zombies, is Skysovereign, Consul Flagship. I side this in versus any white deck. It helps deal with Planeswalkers and creatures while developing the board. It is a hard to deal with Vehicle threat gives Zombies another angle of attack. It keeps you from being linear, and enables powerful swings in games where you are behind or you have an undeveloped graveyard.
After toying on Magic Online I found Zombies to be a bit disappointing regardless of my success at the classic. While it beats Vehicles routinely, I found the Flash matchup more troublesome than anticipated. The biggest problem is Gideon, Ally of Zendikar, which is almost impossible to answer through any additional resistance. B/G Delirium is even worse, which I expected, at least; Ishkanah, Grafwidow into Emrakul, the Promised End is not a curve you can often beat. The sideboard needs work, as some of the cards such as Skysovereign, Consul Flagship and Spell Shrivel more than impressed me, but other inclusions were lackluster.
It's possible that Zombies could find a place within this metagame. Perhaps moving back to Elder-Deep Fiend emerge versions is a solution. Kozilek's Return and Elder Deep-Fiend should be solid. Those versions were much less consistent, but in order to compete with decks that are clear powerhouses, sometimes you must eschew consistency for raw power. The Zombie shell of Cryptbreaker/Haunted Dead/Prized Amalgam will always be strong enough to see play one way or another.
If you are interested, make sure you get in reps with Zombies and try out the different versions. Work on developing the sideboard to address the weaknesses and perhaps you can find some additional non-apparent breakout options.