The next historic expansion for World of Warcraft, Wrath of the Lich King, will land in WoW Classic in 2022. This will let all players create death knights at level 55, as well as increasing the level cap to 80 -- if that seems like a long way off, there are XP boosts you can pay for to get you up to level 70, but you'll have to grind the rest of them yourself.
WoW Classic has maintained steady popularity since its long awaited release in 2019. Its main focus was to recreate the original World of Warcraft experience as it was in its 2005 release. Since then the main Classic game mode has splintered into different server focusing on different eras, with the main one moving steadily through the expansions. The first was Burning Crusade. Up next is Wrath of the Lich King.
The original Lich King expansion hit World of Warcraft's mainline servers in 2009, and brought with it some of the most beloved dungeons and raids yet seen in the game, including the 5-player Azol-Neruib, and the 25-player siege of Naxxramas. All of them will return, alongside the two new Northrend zones with their chill themes, providing new adventure for players new and old. The Inscription profession will become accessible, letting players inscribe magical glyphs into trinkets and off-hand items to change their spells and abilities.
One part of the Lich King expansion which won't be added with this release is Dungeon Finder. This controversial grouping tool was one of the reasons so many players wanted a WoW Classic experience in the first place, so preserving the more social, if more difficult, method of finding people to raid with will be maintained following the expansion's release.