Schutz (no "l" in the name) created that structure, and yes, avoided typology, saying it was measuring changeable behavior. Another guy, named Ryan, came along and created a "map" of the score grid, which did give names of the different score ranges (9 for Inclusion and Affection, and a 10th in Control), though still said these were changeable behaviors.
A couple, named the Arno's, licensed the system, but mapped the four temperaments to it (and discovered "extra space" so to speak, that did not fit in the ancient four, and so became a fifth). Temperament, of course, is apart of an inborn typology.
In my studies; I've determined that Inclusion corresponds to Interaction Styles (E/I + NP/SF; NJ/ST), and Control is Keirsey's groups. (S/N + J/P).
I forget if Schutz or Ryan ever used the terms introvert and extrovert. They might not, since they don't believe this is really apart of the person. But yes, it is their grid that implies those terms as well as ambiversion, when extended to inborn temperament.
Since this system is based on a 2D 10x10 grid, scores of 4 or 5 in either dimension are considered moderate. Since low expressed Inclusion (eI) scores correspond to "introverted" temperaments (such as Melancholy), and high eI scores correspond to extroverted temperaments (Sanguine, Choleric), then eI of 4 and 5 is technically ambiverted. In MBTI, they will still have to be either E or I, but they may have difficulty determining which.