Considering all the plans to revisit and maybe hang around on the moon, this sounds like an excellent reason to have a radioisotope-powered lunar probe or few doing continuous seismic monitoring. (IIR, even the crash of an Apollo LEM upper stage was enough to echo around in the moon for an hour, as recorded by short-duration seismic instruments the astronauts left behind.)

OTOH, given our recent track record landing lunar probes intact...yeah. Easy to see why nobody would suggest that.

So maybe: The moon does have an atmosphere, with a total mass of 10-ish tons [Wikipedia]. If we had a lunar orbiter watching that atmosphere (spectra as the moon eclipsed stars, or whatever), it seems like a meteor hit far smaller than this one would be obvious. Dunno if you could also spot traces of the deorbit and landing burns of spacecraft headed to the moon - but the prospect of that might shake funding loose from countries which felt themselves to be racing to land on the moon.