UPDATE 6/11/18: Blizzard has dismissed the claim it intended to announce Diablo 4 at BlizzCon 2018 last weekend - an event which ended up being overshadowed by Diablo's sole appearance as a much-maligned mobile spin-off.
In a statement to Kotaku, which published the original story, the publisher stated it did not "pull any announcements from BlizzCon this year or have plans for other announcements".
Kotaku sources contend Diablo 4 is very much in development (no surprises there) but also that plans to announce the game were once afoot - even if these plans were never actually destined for a Blizzcon announce after all.
ORIGINAL STORY 5/11/18: The fallout from this weekend's BlizzCon, which saw Blizzard vexing core fans by ending its opening ceremony with news of a Diablo-themed mobile game, has yet to abate. However, a new report suggests that Blizzard had, at one point, intended to close with word on Diablo 4.
Much of the backlash following Friday's Diablo: Immortal announcement seems borne of a belief that Blizzard is wilfully neglecting its core audience in favour of a new casual market by prioritising mobile over PC. And many have suggested the outcry could have been avoided if Blizzard had accompanied Immortal's unveiling with news of the next mainline Diablo game.
According to a report by Kotaku, however, that's precisely what Blizzard had originally intended to do, following its Immortal segment with a video in which company co-founder Allen Adham would reveal that Diablo 4 was in the works but not yet ready to be shown. Sources told Kotaku that this initial plan only changed within the last couple of weeks, and occurred because the Diablo team - which has purportedly already seen two different iterations of its new game under different directors - is not yet ready to commit to an official announcement.
Instead, Blizzard attempted to temper fan expectations ahead of BlizzCon, writing that, "We currently have multiple teams working on different Diablo projects and we can't wait to tell you all about them... when the time is right. We know what many of you are hoping for and we can only say that 'good things come to those who wait,' but evil things often take longer."
That's the line it's chosen to double down on since Friday's events, with Diablo: Immortal's lead designer, Wyatt Cheng, reiterating to fans during a BlizzCon Q&A panel that "We want to say that we hear you, and we have multiple projects - Diablo projects - being worked on by multiple teams. Diablo Immortal is one of those projects we're very excited about, but there are others." However, Cheng, too, fell short of invoking the magic words "Diablo 4".
At this point though, it's doubtful if even those words would be enough to placate angry fans. Indeed, if reports are accurate, it seems remarkable that Blizzard, having correctly anticipated Immortal's reception and outlined a plan to appease its core BlizzCon audience, would willingly jettison those plans and risk invoking the wrath of its dedicated community.