Get used to Highlander decks being a dominant force in Wild for the foreseeable future.
Zephrys, Reno, Kazakus, and Dragonqueen are each capable of turning the game around, so they are more than worthwhile to build a deck around, and since Standard requires the same tools every year, Reno decks in Wild just get more and more consistent, as duplicates become unnecessary. Just for board clears, Priest has accumulated Mass Hysteria, Dragonfire Potion, Lightbomb, Psychic Scream, Plague of Death and now gets Soul Mirror. If you need earlier answers, there's Duskbreaker, Breath of the Infinite and Spirit Lash, and if that still isn't enough, Zephrys and Kazakus can help you out anytime. And the next one will likely come out later this year or next year.
Inevitably, Highlander decks get stronger, and become more interesting for other classes as well. The reason not everyone is playing Highlander, is that these decks need win conditions that beat other control decks. Mage has the Quest and used to be the only good Highlander deck, and now with Raza restored to its original version, Priest has again obtained something that may end the game in a similar fashion. You can bet that as soon as Warlock gets a win condition that is easier to complete and more consistent than Mecha'thun or Darkest Hour, Warlock will go back to playing Reno as well. It's got all the necessary tools, just no card or combo that is one the level of what Mage and Priest can do.
Other strategies actually have a harder time improving. Non-Highlander Combo decks like Quest mage, which can deal 30+ damage uninterrupted, have a pretty good chance to stand against Highlander decks, but most combo options are designed in a way that they take a long time to be completed, and Wild will never be free of fast decks that try their luck to end the game before Reno shows up. I think it's fairly unlikely that any new combo deck will be as fast and resilient as Quest Mage, anytime soon. There's the new Miracle Jade Druid, but I think that deck can only succeed as long as nobody sees it as a threat. Any Highlander deck can easily include Skulking Geist.
Aggressive decks can't get much stronger without becoming an issue in Standard as well. There's a limit to how strong 1- and 2-drops can be made, and cards like Sea Giant are already seen as too strong in Standard. Secret Mage is one of the few successful aggressive decks, since it doesn't really need minions past turn 5 and Counterspell can be difficult to deal with.
I think Midrange decks could be a counter again, if they get tools to establish boards that can't be dealt with, and quickly enough before inevitable win conditions hit. A card like Vivid Spores is the right direction, I think, but probably not good enough yet. Combo disruptors would also be an option, but they are very uncommon as well, and not a top priority in set design for Standard.
In short: HIghlander decks are very unlikely to disappear anytime soon; possibly never. If you are sick of Highlander, either play a combo deck, or try your luck with something very aggressive, and look out for cards that have the potential to make healing and board clears meaningless.