There's much more to this story and interesting that information is leaking out.
Why aren't we seeing detail on the flight path, how it manouvered and where it and the `projectile' broke up - even only to the level of detail of `over the south west Pacific?'
It's not as if most of the capabilities of the `national technical means' that likely observed it aren't know about.
There's a lot of popular media hype about Chinese hypersonics - recent articles about standing oblique wave detonation engines etc.
But when you dig much deeper - they don't stack up.
FOB systems aren't new or difficult - some classes of MIRV have long been able to move up, down or cross range.
Extraordinary claims require extraordinary evidence.
ADDING: So now The Independent gives us a bit more detail. Apparently the terminal phase happened over the South China Sea.
https://www.independent.co.uk/life-s...-b1962256.html
A more informed article here:
https://www.thedrive.com/the-war-zon...body-knows-why