This is the Diablo you pictured, right?
Diablo 4 art

Yesterday, Blizzard took time away from appeasing China to kick off their two day BlizzCon event for 2019. One of yesterday's big reveals was the announcement that Diablo 4 is coming. What they didn't share in their reveal announcement to the public is the fact that Diablo 4 will require an online connection.

Not only that, but Diablo 4 will include microtransactions. Of course, all of this has a chance to change over the course of development, but I wouldn't hold my breath if I were you. Speaking of development, it seems as though Diablo 4 is still a long way away from being released. Blizzard says that Diablo 4 is "not coming anytime soon." Diablo 4 director Luis Barriga continued to say that it's not even coming "Blizzard soon."

The reason that Diablo 4 requires a perpetual Internet connection is because that's what the lead designer, Joe Shely, feels is best for the game.

"There's a large, seamless, connected, and shared space in the world, going down into dungeons, being able to group with your friends, trading and PvP. We feel that the best way to experience that is in a world that is online,"
You will reportedly be able to play solo, just not offline. Diablo 4 will include world events, towns that serve as a social hub for players, PvP zones, and an open world that will have you running across other players from time to time.

Diablo 4 will also make use of microtransactions. According to an interview conducted by Quin69 on YouTube, Diablo 4's microtransactions will be included for things like cosmetic items. Microtransactions may also be present to allow players to increase their stash size beyond the base size. Diablo 4 will also include more traditional paid content like expansions. Obviously, with the release being so far away, the specific details on what will fall under the microtransaction umbrella have not yet been ironed out.

Though the game is still a ways away, fans are also already taking issue with Blizzard's desire to "simplify stats" on character progression, weapons, and gear. A number of Reddit posts on the Diablo subreddit have popped up voicing their disdain for something that the fans feel is an oversimplification of the game and an extreme catering to more casual players.