>Aegis BDM is designed to hit hypersonic reentry vehicles
Ballistic hypersonic reentry vehicles. The entire point is that these new weapons are maneuverable in the atmosphere at mach 8+ all the way to the terminal phase.
They don't maneuver for shit in the terminal phase. Boost-glide weapons avoid mid-course interception by staying relatively low in the upper atmosphere rather than following a high ballistic trajectory well into space. Once they're in the terminal phase their maneuvering capability is comparable to older maneuvering reentry vehicles (which are nothing new; the novel part is skipping the ballistic mid-course phase.)