I'm neutral in my point of view of it.
I have access to all platforms so it doesnt really affect me much.
I see one pro and one con though.
Pro - Blizzard games could potentially come out on Steam but then again Minecraft is still non-store exclusive on PC.
Con - There's a chance mismanagement could happen like Rareware 2 decades ago but its too far early to see what will happen now, we'll know in a few years with Bethesda.
Either ways, doesnt matter to me - I already have Activision/Blizzard games across Playstation, Xbox, Nintendo and PC platforms already, so it helps not being restricted to investing in one platform exclusively.