The "fault" that WoW is making eyes at a singleplayer mode, between many quotes, is Tim Jones and his team. The main designer of WoW Classic, which you already know is a version of the original game as it was in 2006, has spoken with Forbes about the news of the Hardcore mode that the game will release and some playable details that Blizzard is saving for the future. .
Among the good list of additions, Jones has confirmed that the team is working on that solo game mode, also known as "solo self-found", which has its roots in other games like EverQuest and Path of Exile. "We are planning to add a mode that allows players to set that restriction on themselves and some way to show other players that they have taken up this challenge. It will be released in the future," says Jones.
In this case, although WoW is made based on interaction and the massive world, the players self-impose a series of rules such as not interacting with other players, not trading with them, or not grouping with others. The only exception to this self-enforcement is in dungeons, where grouping is allowed. Of course, among the rules the official servers of Classic Hardcore prevent you from being able to access one of these dungeons more than once a day.