[the_third_wave]

They can not be shot down (yet).

[apple4ever]

Probably because they can't actual fly yet either.

(That's a bit of a joke but hypersonic missiles have a lot of physics challenges to overcome before being viable)

[profile53]

Why not? As a layperson, I assume a CIWS could still fire into the flight path of one and knock it out of the air.