Blizzard has followed a trend in recent years of reviving some of its classics. It did it with StarCraft: Remastered, presenting an improved version of the original and went even further with Warcraft III: Reforged, remaking most of the original game (curiously the latter ended up being very poorly received by the fans).
If Blizzard has revisited StarCraft and Warcraft, logic tells us Diablo is next, and that is precisely what French website Actua Gaming is reporting. The site refers to "sources that prefer to remain anonymous" when it states that Diablo II will indeed be reappearing in the form of Diablo II: Resurrected.
Although Blizzard would naturally be involved, the site reports that it is Vicarious Visions that is working on the bulk of production, with the goal of releasing Diablo II: Resurrected in the last quarter of 2020. Vicarious Visions has an excellent relationship with Activision Blizzard, having worked on the remakes of Crash Bandicoot and the Destiny 2's PC release.
Interesting information, which seems plausible considering the enthusiasm surrounding Diablo IV and the recent trend of Blizzard towards remasters, but as it stands right now, nothing exists in official terms.