Eventually I think they will, just because the chipsets are becoming closer together, and iPad/iPhone hardware is cheaper than Mac hardware. But they can easily do this in software for the Apple TV, and honestly they should have done it already.And the MacBook air probably never will support it.
They need extra hardware, like a compass and such.
I think it is funny, Apple gives us Spatial Audio for the airpods with iPhones and iPads, to have better experience when on the go, and what everybody does is complain it does not work on all their devices
The problem with ATV is that the "box" can be placed anywhere, and so the position of the box doesn't matter (Unlike with iPhone/iPad/Macbook) All they have to do is have a configuration screen that pops up when you connect or turn on spatial audio that asks you to look at the screen and push a button. Basically calibrating the screen position manually.