Most nations are not eager to advertise their satellite reconnaissance cababilites, so that’s probably why China waited. It might have something to do with protecting the location of their satellite, if it’s a classified bird. So they waited..
Most nations are not eager to advertise their satellite reconnaissance cababilites,
Probably.
Fictional (?) scenario:
China's State Administration for Science, Technology and Industry for National Defense announced that they have dispatched USS submarine to investigate under-sea wreckage.