I hope so but this type of finding has been wrong before. See the recent discrediting of liquid "brines" on Mars: https://www.sciencedirect.com/science/article/pii/S001910351... Until a rover or other probe tests it directly, I'll remain skeptical.
We have long known that there is tons of frozen water on Mars outside of the poles. Through many individual discoveries we've learned about shallow subsurface permafrost over much of Mars; we've learned of a long history of sizable quantities of liquid water on Mars; and we've learned of subsurface glaciers of very ice that are almost entirely water ice by volume. The brines research is still an open question, as in all scientific research there is a back and forth between different interpretations of the given data, it's quite possible it will ultimately not shake out as a valid interpretation (but it's also a bit much to say that the brine theory has been "discredited" merely because an argument was made against it). Regardless, the existence of subsurface glaciers, of which this is an extension of, is a far less controversial result. We know Mars has subsurface water ice, we know some of that is in the form of glaciers, these are merely certain examples of those glaciers that are significantly exposed to the surface.