Unlike typical ballistic warheads, which fly on predictable trajectories as they fall from space to their targets, hypersonic projectiles can change course, making them more difficult to target.
The author doesn't understand what they are writing about. Hypersonic has nothing to do with manuevering, it's a speed definition. Anything traveling at Mach 5+ is considered hypersonic. Western countries already have access to systems that defend against hypersonic missiles. The ability to change direction has nothing to do with being hypersonic.