The loitering capability suggests it's not logistics (it'd be much cheaper and easier to send it ballistic).

Messaging is a good guess, though. Launch it at the start of a crisis and then threaten to de-orbit it on top of an opponent unless they cease fire / withdraw / negotiate etc. Doesn't really matter what's in it, the important part is that it's a concrete demonstration of capability & intent.

Unlikely to worry China or (possibly) Russia much, but would likely be pretty effective against second tier powers.