Far too many rumours have been spread about a possible Diablo 2 remaster; Blizzard design lead David Brevik suggested before on a PC Gamer interview that it’s difficult for the company to do because “a lot of the assets [didn’t] survive”.
Of course, a remaster is too good to pass up because that’s what sources are claiming is happening. French site Actugaming cited that Activision subsidiary Vicarious Visions is working on a remaster scheduled for the fourth quarter of 2020 called Diablo 2 Resurrected.
The French site was one of the few who called the Diablo 4 and Overwatch 2 announcements shortly before they were made public at BlizzCon 2019; they may be a bit more reliable in that regard. Still, it’s nothing official, so take it with a grain of salt.