You're going to be hard pressed to out pedantic NASA scientists. They probably spent quite some time deliberating over the term "Ice Deposit" as the most accurate one.
There is a sentence that seems to imply that the frozen status implies there is no life. I'm not so sure we can be sure of that. There are microbes on Earth that basically live in virtually frozen environments. (All you need are moments when the water is liquid.)
All you need are moments when the water is liquid.
But you don't get those at such low atmospheric pressure. Mars atmospheric pressure is around 600pa. Below 611pa, the boiling point of water drops to the freezing point; you can have ice or steam, but not liquid water.
They do have recent satellite images that appear to show signs of water running down ravines at certain times of the Mara year. Don't have a citation handy, though.
You could even just have life that moves more slowly because of the lower available energies. If we ever find some life that does not have an Earth origin perhaps we can finally get some more data points about what environments are really required for life.
It is not mud. Firstly it is not liquid, it's frozen. Secondly, it's not permafrost where it's mixed with a considerable amount of dirt, it's ice, a sub-surface glacier, one of many on Mars, merely the largest one we've discovered so far.