I don't understand on what basis. Hegel isn't neo-Kantian, but is quite clearly post-Kantian (not only in chronological terms but also in terms of his argument). Hegel doesn't seek to answer Kantian problems, he demonstrates the aporetic nature of the way he frames the questions...
I would say Hegel was for the main anti-Kantian with small bits of Kant nevertheless absorbed (basically the transcendental dialectic without the transcendentalism and the "speculative" nature of the synthetic a priori without the synthetic a priori).
In terms of the philosophy of mathematics (which interests me if nobody else ) Hegel was plain anti-Kantian and could be seen as pre-Fregean and a fore-runner to analytic philosophy.