As usual, the Game Developers Conference offered plenty of panel discussions, presentations and keynotes, and one of the many developers participating was Blizzard. Among other things, they had a presentation behind closed doors on the status of World of Warcraft - and it turns out that it is more popular than it has been in a very long time.
In a thread on Resetera you can find the slides that were used, which among other things reveal that World of Warcraft currently has 7.25 million monthly subscribers with an upward trend and is more popular than in a very long time. We also learn that the launch of World of Warcraft: Classic was immensely popular and exceeded all expectations, sending the number of subscribers to over eight million.
Another thing revealed is that World of Warcraft: Shadowlands disappointed a whole lot of players, but that Blizzard's commitment to greater transparency and better dialogue with the community ultimately led them to regain trust.
To sum it up, do not expect World of Warcraft to disappear for a long time, on the contrary, it seems to be something we will see more investments in the future.