Beware of tolerances. IPC-class 600 allows for quite big negative tolerances on via hole diameters. (Class 1 is -50% if I remember well.) Fabricators follow this, and havequite big negative tolerances in via; some put it on their website, for example, Tolerances on Printed Circuit Boards - Eurocircuits. Quite logical, if a via hole is indeed a via hole the diameter is not terribly important.
The Gerber tells it is a via, so it tells you are OK with the high tolerance, and whatever they do with vias.
I would not say it is a via when it is not.