Yeah well, I'm sure there are enough big brains at Valve to figure something out! But it would sure put the expectations to the roof.
Big brains is only part of it.
You need to have world-wide distribution, which means you need to build relationships with retailers worldwide in order to have these things on as many shelves as possible.
You need to have actual marketing now, guerilla efforts like they did in the past will have v.limited efficacy when it comes to pushing hardware (which MS is discovering rn), you now need to be on billboards and bus stops, which costs massive $$$ and needs people to run.
They will easily have to at least double in team-size to make things work, and you will almost certainly have to have a hierarchy in there too (logistics and distribution need that kind of organizational discipline in order to gain efficiencies).
It's an entirely different ball-game than what Valve has been doing.
Again, I'm sure people would ask for HL3 over and over. Who knows though, they did it with Index.
The Index is barely making a blip when it comes to sales and awareness of VR devices, especially when you compare it to how much Meta has done in the space.