Agree with all the other comments saying this specific connection seems iffy and rather unlikely. The many significant differences cited are strong evidence, G and Q and R are entirely different. The most distinctive feature of Visa aside from the stencil dropouts is the missing ‘lost and found’ strokes with A, N, V, and W, and Quake’s font doesn’t have this feature at all.
On top of that there are a billion stencil fonts! There are thousands of them that narrow near the stencil dropouts. Seems like the author is making wild speculation.
The Q is obviously custom (Q for "Quake") the question is where the starting point for the font was. I agree about the cherry picking, but the font is going to have been modified for the game (as evidenced by the "Q".)
On top of that there are a billion stencil fonts! There are thousands of them that narrow near the stencil dropouts. Seems like the author is making wild speculation.