Well, the article refers to a MIXTURE of various components, so the description is instantly rendered irrelevant to the claim of hot WATER vis a vis cold WATER.
The Mpemba effect is the observation that warm water freezes more quickly than cold water. The effect has been measured on many occasions with many explanations put forward. One idea is that warm containers make better thermal contact with a refrigerator and so conduct heat more efficiently. Hence the faster freezing. Another is that warm water evaporates rapidly and since this is an endothermic process, it cools the water making it freeze more quickly.
None of these explanations are entirely convincing, which is why the true explanation is still up for grabs.
Since I’m not conversant in the physics, all I can do is google-fu, and there seems to be consensus that the phenomenon occurs, but no one knows why.