I have three problems with this. First and most important is our own grotesque lack of planetary models upon which to formulate theories about why things look the way they look. We have been able to study the surface of one planet in detail, and our own geologic studies still have significant gaps. It is presumptious to announce that whatever happened here must also happen on Mars.
The second problem is noted in the article. Where did the water go?
The third problem is more important. Where did the water originate?
1: Mars is avery ordinary rocky planet, not that different from Earth. Water is still water on Mars, as are dirt, rock, gravity, heat, wind, etc. Mars is not a place where you can imagine a different physics, a different chemistry, or altogether different outcomes to similar physical processes.
2: Most Martian water evaporated into space over a long period of time. Obviously, some remains. The Martian gravity well is far shallower than Earth’s.
3: Martian water originated from the same place that terrestrial water originally came from: accretion of water ice bearing material and hydrated minerals in the solar accretion disc. This is the same place that everything now found on all the planets planets came from: rock, metal, gases, water, hydrocarbons, etc. Where do you think it came from? Do you know of any other source? If so, please share.