This is a pretty common joke/expression among mathematicians i.e. "As you all know from kindergarten abelian groups are just monoidal groupoids with a single object" or whatever.
I understand "vector calculus" here as meaning "how to compute stuff with vectors", i.e. adding and subtracting vectors, computing the inner product etc.; not doing calculus with vectors. Obviously both interpretations are possible, but the latter is usually called multidimensional analysis.
Surely (multidimensional) analysis is the term used in mathematics for a more rigorous investigation of the basis of calculus. In physics, vector calculus is taught as a tool and the course is called vector calculus (or maybe multivariable calculus.)