Once Valheim came out, I didn't need any other Survival games. To me, it was the final evolution but it's unfortunate their development cycle just went completely off the rails. It seems to be much better now since they're already teasing Ashlands pretty heavily in addition to pretty regular patches so maybe that was COVID's fault or the fact they couldn't keep up with growth.
There's several other decent options for survivor type games outside of Valheim so I'm not sure why Blizzard wants to fool with this project. Maybe they have a piece to survival that will take it to the next level but by the time it comes out, I don't think anyone will care.
Decent options is all there really is. Conan Exiles, Ark, either of those are fantastic titles. But one wouldnt say that they are refined by any means. Every single game thats a survival game that Ive played has been some jhanky ass unfinished shit. Only after the titles have been out for half a decade do the resemble some form of a complete game. Its been the perfect hive of indie companies because they can get away with less than they normally would by releasing in "alpha" and like Valheim has displayed - take their sweet ass time with updates.
If you need more evidence for why Blizzard Activision would want to get in on this - Minecraft has been playable since around 2009 with a retail launch in 2011. Its lowest year in profit was only 165 million in 2014, with its most profitable year in 2018 iirc at 500 million. The game overall has made an estimated 4 billion+ dollars since its release. Thats including is mobile counterpart, which has seen more success as the years pass on it as well.
Now take into account that anytime you have played these games and had the MOST fun - you were playing with someone else. Sons Of The Forest is the most recent survival game my g/f and I have purchased - it is in such a bare bones state that by myself, I already know the game would just be awful. But together, the game is actually fun and the jump scares are hilarious.
Now take Blizzard and refine that formula down to where you have a girth of content available at launch, (aint no alpha purchase BS here), and you have excellent multiplayer options (whatever they decide) to keep you active. Its a recipe for success and Im surprised this idea hasnt reached the boardroom far before 2023, or hell, 2020 for that matter.
Lastly - it sounds like Riots MMO is also going to have some "Survival" elements to it. Which probably lit the fire under those very same boardroom suits to begin with.