True. Even glider HGV and manoeuvering hypersonics (so not counting typical ballistic style AShBM) can be potentially intercepted since the relative velocity allows this possibility.
It is all about the position of the interceptor and the position of the target of the hypersonic weapon. If the interceptor is basically on the target such as on a ship, then it is possible to intercept, just extremely difficult and much more prone to error compared to ballistic.
But it should be said that even traditional ballistic trajectories are hard to intercept in real world conditions. Iranian missiles using using ballistic and predictable trajectories and relatively low energy (SRBM and MRBM) can still penetrate the best western and Israeli air defences in Israel, UAE, Saudi Arabia and Kuwait (and I think others too).
So ballistic only is dangerous enough. HGV and moving hypersonic is just that much harder to intercept in mid course and terminal phase.
In any case, the most difficult part of the AShBM is the targeting and "seeker" rather than the missile itself.
