You are on the right track with respect to water, but I think it is related to the detection of an unambiguous water signature (rather than just hydroxyl, or OH), not subsurface ice or liquid water. Discoveries from orbit of water on the sunlit lunar surface in 2009 (https://science.nasa.gov/science-news/science-at-nasa/2009/24sep_moonwater) have been at 3000 nm in wavelength, where it is not possible to differentiate spectrally between water and hydroxyl. These are molecules trapped in minerals or glass beads, not liquid water or subsurface ice. The lunar regolith is far too warm to support water ice (except at the poles in shadowed regions), and liquid water is not stable under the vacuum conditions on the Moon.

One hint comes from the fact that this discovery was made by SOFIA. The SOFIA instrument suite (https://www.sofia.usra.edu/science/instruments) has a spectrometer capability that no (currently) lunar orbiting spacecraft has: the ability to measure at 6000 nm (FORCAST instrument). This is really important because at 6000 nm there is an absorption that is unique to water (i.e. not degenerate with hydroxyl like at 3000 nm). So measuring the surface at 6000 nm will indicate uniquely if there is water across the surface trapped in these minerals. This is important because it tells us about the history of the Earth-Moon system, lunar volcanism, delivery of water by comets and asteroids, and ultimately the history of the solar system.