According to the Le Monde newspaper (article here in French) Blizzard has demonstrated a version of Diablo 4 to developers in France.
According to Le Monde, the demo took place in Versailles but was overshadowed by talk of job cuts as Blizzard tries to cut its workforce in 2019.
Most of Blizzard's current titles, World of Warcraft, Starcraft and Diablo etc are gettin g long in the tooth now but the latest version of Diablo isn't expected until 2020.
Originally released in 1996, Diablo is one of the biggest games in the world, with a massive online community contributing to Activision Blizzard's profit margin.
In 2016, the 20th anniversary of Diablo, two former developers David Bervik and Bill Roper tweeted hinting at an imminent release of Diablo 4;
At the same time there were rumours of an announcement at BlizzCon 2018 with talk of a release date for Diablo 4. This was apparently removed at the last minute and replaced with a version of Diablo for a Smartphone instead. The same article discusses the many different directions the new version has taken whilst in development have caused the current delays.
At the same time fans were left frustrated when a goody bag containing a Diablo4-branded set of dice leading many to speculate that a release of version 4 had been planned but withdrawn at the last minute.
Despite all this controversy and uncertainty at BlizzCon 2018 though, some argue that version 4 is imminent.
Well, again from Screenrant we can assume that expectations are high! We also know that Blizzard is taking as long as it deems necessary to get this version right after the internal disappointment with the release of Diablo 3.
The same article also speculates that the next version will be "dark and more gothic", in contrast with what many people see as the cartoon-like graphics in some parts of version 3; particularly the Gothic World of Sanctuary.
Apparently, v.4 will be designed to be much more social the previous versions, where players will be able to gather and trade online.
Some would say remarkably little.
In their announcement of BlizzCon 2019, there doesn't seem to be any mention of Diablo 4, only a promise of "the latest news on everything Blizzard".... Watch this space!!!