The DY-100 was a choice from the 60's, everything after that ramped the level of technology down as there had been 20+ years to see that that wasn't happening as they showed. In TNG season 2 another DY series ship, a 500 is shown, Data's analysis of the information concludes that even the 500 was designed as a cryo ship, generational journeys.
Travel between planets meaning the sleeper ships travelling well below the speed of light taking decades or centuries at least to make it to orbit, and by a miracle, maybe landing alright.
Terra Prime shows that the lunar colonies are relatively new, sometime in the order of decades after first contact and being the newest series taking precedence by showing more of a time period much closer to the launch of these ships, ones like the Conestoga that settled the Nova colony.
So there was nothing manned on the Moon in 2063, or everyone on it perished because of the war leaving them no food. Even Earths own technology was minimal, and with the Western Alliance/Eastern Coalition having such terrible governments into 2079 at least, no one was going to notice or believe stories from the other.
The small Vulcan ship had the only functional sensors necessary, and they were too focused on directing their scans at the planets surface looking for signs of habitation/power/landing sites. And we know from TOS and Enterprise, Vulcan's only scan what they feel like, and can be surprisingly blind to everything else.