Any fan would be nervous when an anticipated game stays relatively quiet while it's in development. Although the saying goes that no news is good news, it's hard to take that on faith. However, a lull in announcements on development can also mean that work on a big part of the game is under way, and the studio is cleverly building up anticipation. That might be the case with Diablo 4. Word is that the game is progressing well in spite of obstacles created by this year's pandemic. With that in mind, Blizzard might be keeping quiet on purpose so that the next Diablo 4 reveal gets even more attention.
The question then becomes what Blizzard could be working on that it wants to be such a big deal, and perhaps one possible answer is that it has a brand new Diablo class in the works that it wants to surprise fans with. It's well known that Diablo 4 still needs two classes to fill out its starting roster, and while the three known classes may indicate that Diablo 4 will be full of callbacks and returning classes, they are in no way a confirmation. Instead, there's still the distinct chance that Blizzard will surprise players with a brand new class with functionality unlike any other.
The Diablo Family Tree
Classes have already gone a lot of directions in the Diablo franchise. Some of those directions turned out to be more fruitful than others and were even fortunate enough to become mainstays of the series. For instance, the Barbarian has had the opportunity to be in every game since Diablo 2. Although it's seen plenty of variation on the theme and adjustments as the games changed as a whole, the Barbarian has always been there for players eager to play a brutal weaponmaster ready to rage their way through an encounter with demonkind.
Similarly, classes have returned in different incarnations while still playing on a lot of the same themes. Perhaps the best example is the Wizard, which any Sorceress player could pick up without much adjustment. Although the Wizard has a few unique tricks like Arcane magic and more reality-bending spells, it still operates on the same basic principle as the Sorceress, full of powerful elemental magic that can dish out an onslaught of ranged damage.
What all of these classes exemplify is that although Blizzard has a rich sense of tradition as far as Diablo classes are concerned, it also knows that experimentation is a good thing. It isn't afraid to try bold new things and take unfamiliar perspectives on familiar content in this area, especially when making new classes. The Diablo class roster has already covered a ton of angles, so one might expect it to be hard to find areas of design that the developers haven't covered yet. That hardly makes it impossible, though. Whether it means retrying some of its oldest ideas or making something completely new, Blizzard has a lot of options if it wants to add a new class in the next game.
A Few Possibilities
One concept that Blizzard might try would involve fulfilling an archetype that doesn't exist in Diablo 4 yet. None of the three confirmed classes use holy magic like a Paladin or a Crusader, so maybe something like that will appear. However, none of the games contain holy characters fully focused on using their magic. Something like a Priest or a Cleric would hardly be out of Blizzard's expertise -- it's one of the core classes in World of Warcraft. Although it's unlikely that there's room for another Intelligence based spellcaster in Diablo 4, a caster who can call down light magic, the help of holy forces, and some valuable support skills would be fascinating.
Blizzard might also make a relatively new class by reviving an old idea. Diablo 1 was supposed to have a couple classes that went unfinished. One of them was the aforementioned Barbarian, which has been lucky enough to grow into a franchise staple, but the other hasn't been revisited: the Bard. Blizzard could find some really unique design space with the Bard by making it a Dexterity class while still leaning into classic RPG tropes of the class and giving it plenty of useful magic, good for distracting and controlling enemies and even dishing out some damage.
One more concept that Blizzard could look into is something like the Death Knight, another class featured in WoW. It could make an excellent Strength based class alongside the Barbarian, playing somewhat similarly to the Crusaders and Paladins of Diablo's past, but wielding more aggressive dark magic than its holy counterpart. Diablo is hardly afraid of giving players dark magic, considering the Necromancer has already featured in two games, so something similar but more durable like a Death Knight seems like a welcome addition.
The Big Reveal
Blizzard is really keeping players in suspense with the last few classes, as it's been close to a year since the first three classes were all revealed together. With that in mind, Blizzard might be planning on doing the same thing with the last two classes, especially if they're brand new. The first three classes, all returning veterans, were revealed as a package, so it would be a clever parallel to reveal two brand new classes in a shared event. Diablo 4 is said to be the start of something big in the game's world, so it would be fitting to demonstrate that by showing how the games are evolving with a reveal like this.
To date, no Diablo game past the first one has gone without a new class. While Diablo 2 was almost entirely new classes out of necessity, Diablo 3 still introduced players to plenty of new options like the Demon Hunter, the Witch Doctor, and the Wizard. If anything, it would be surprising if the next game didn't offer at least one new class. An addition like that would be a big draw for the game, compelling players to try the new game instead of remaining satisfied with Diablo 3's seasonal events, replaying familiar and similar classes. Not only would a new class or two be huge for Diablo 4's publicity after this lingering quiet, it would help make it a new experience, even as the game openly experiments with new elements. The more diverse the class roster, the better.
Diablo 4 is in development for PC, PS4, and Xbox One.