Speaking as a player of VR games and not as a Rioter here (I am not working on the MMO, in charge of any game development, or indeed working on any game), I don't personally feel like VR is mature enough or accessible enough for an MMO yet. We're barely seeing companies investing in (triple A) single player experiences. The hardware to have a competent VR game is still really expensive, with the only alternatives being things like the Oculus Quest with onboard hardware, subsidized by ads. That, and there's a pretty heavy space requirement too.
I would love to see a VR MMO (Though, a VR MMO would likely have to be substantially different from what we consider normal MMOs to be like), but I think it's got quite a way to go before we start seeing triple A multiplayer games on VR, let alone massive multiplayer ones. I'd also be really interested to see what a control scheme in a VR MMO would look like, given that MMOs tend to typically have many more buttons to press than standard controllers have. Some VR games are experimenting on this with gestures but many MMOs require the ability to press buttons faster than you could possibly perform gestures. Imagine drinking a potion while activating a buff and then performing a combo in the real world in the space of a GCD, which in something like WoW is three button presses in <1.5s. And that's without getting into targeting reticules.