I would caution against thinking too hard and trying to re-invent the wheel; we would just call this an ascent or descent. If you want to be really fancy you could maybe say something like a "registral trajectory," but come on now; that's just silly :-)
A relatively new field in music theory is called "embodiment" (or "embodied music theory") and it discusses the physical connections to music performance. It's possible you could discuss locations on the guitar neck from an embodiment standpoint, but when it comes down to it, you're just talking about an ascent.
Imagine a painting where the far right of the canvas uses only dark reds. We wouldn't really need to come up with a name for that dark red patch; we can just describe it as what it is: a dark red patch that may or may not fit with the rest of the painting.
Typically in scholarship we only feel the need to dedicate a new term if it's a common, innovative, and influential new tactic. If the dark red patches in paintings started to appear in 1863 and an entire school of French artists from ~1860 to ~1900 used dark red patches in their paintings, we'd probably have a name for it.
But turning back to music, sometimes things go up, sometimes things go down. Unless there's a clear trend that's a result of it, we can probably be safe just calling it an ascent or a descent. You could always modify it by describing it as a "chromatic ascent," or maybe as something "descending by thirds," but that's about as specific as we tend to get in this case.