I don't know the article, but there are many sources for the individual claims, e.g.:
* Denver is at 5,130–5,690 ft (1,564–1,731 m) [0]
* The boiling point of water at this altitude is between 201 and 203 °F; at sea level it is 212 °F [1]
* "Your brewer should maintain a water temperature between 195 to 205 degrees Fahrenheit for optimal extraction. Colder water will result in flat, under-extracted coffee, while water that is too hot will also cause a loss of quality in the taste of the coffee." [2]