H2O is not "water". We're talking water-of-crystallisation here - H2O which is chemically locked into the framework of the minerals in question. Sure, it can be extracted by forcing the minerals to reform and recrystallise - usually by heating, but it isn't free-flowing active liquid water.

IMHO, it is further evidence of the long IN-activity of water on Mars. The vast majority of H2O is bound-up into solid forms - ice, hydrated minerals, and possibly clathrates. These solid materials have interesting behaviour. Some flow by slow creep (Martian glaciers), many will exchange H2O as a vapour with the atmosphere - seasonal, and longer-term growth and decay of icecaps, hydrated mineral deposits etc. But the vast majority of the H2O is locked away at depth in the crust.

For many purposes, H2O on Mars can be viewed as a mineral.

We've learned a lot about Mars in the last decade. The high activity of SO2 (Sulphates, extreme acidic brines, destruction of carbonates) came as a bit of a surprise, but in retrospect was well-indicated by analyses of the SNC basalts which showed very high sulphur contents compared to Earth.

Some models have prospered, some have withered. "Blue Mars" is well in retreat. Some form or other of a White Mars may become accepted as the future, but the "colour" of Mars has taken on a yellow tone, from all that Sulphur...