From GameWatcher: “Diablo 4 was the big announcement of this year’s BlizzCon, Blizzard unveiling the upcoming ARPG with a slew of different details. One topic which was only lightly touched upon was cross-platform play and whether or not it will be in Diablo 4.
While cross-platform play was not brought up in any of the major presentations dedicated to Diablo 4, the developer has answered questions regarding it, showcasing interest for the subject.”
Source: N4G PC Diablo 4 Cross-platform Play – Will It Be Supported?