There are some problems with the discovery of phyllosilicates on Mars.

First, the term encompasses a very wide range of minerals, and saying that what's been found is "clay-like" doesn't really help much. "Clay-like" what?

On Earth, phyllosilicates are produced in connection with water. But then on Earth water is the universal liquid, whereas on Mars it may be relatively rare anywhere, and essentially absent at the surface. The presence of ancient phyllosilicates may -- or may not -- indicate a previous watery regime. Could other liquids, such as sulfuric acid, also produce phyllosilicates? The idea seems kind of absurd, and yet, on Mars maybe it isn't.

What I'm getting at is that we should be careful about attributing the presence of this or that hydrated mineral on Mars to the action of water. It may have been something else.

And I loved the passage in the story you linked that said:

The clay minerals were formed at low temperatures (100-200°C) – an important clue to understanding the Red Planet's potential for habitability during the Noachian period.

"What does this mean for habitability? It's very strong," Mustard said. "It wasn't this hot, boiling cauldron. It was a benign, water-rich environment for a long period of time."

As some wag pointed out in comments, 100-200°C is the definition of a "hot, boiling cauldron!" At least it is on Earth.