Imagine if Valve did that bundle again where if you buy an Index you get Half-Life: Alyx gratis, but instead when you purchase Steam Machine or Steam Frame, you get a copy of Half-Life 3
I'm somewhat joking, but this might ironically become true. Valve did develop the Index specifically for Half-Life: Alyx, and they did plan on releasing them alongside each other, but they delayed the game by another year. Wouldn't surprise me if something similar is happening with the new Steam Hardware, given all the rumours and leaks of project "HLX". It might turn out that the Steam Machine is a blueprint for what hardware will be capable of running the future Half-Life game at its max graphical settings, and just like HL:A, it might support VR (alongside flatscreen), hence the new headset as well