Same here. I like to dig into the research behind the published findings. The article I cited was from the west coast and the one you cited was from the east coast. My curiosity and skepticism senses are tingling.
I don't claim to be a scientist or even an expert, but I've picked up a thing or two over the years.
When I took my master composter classes, they claimed that coffee grounds were actually "green" according to MSU literature. That raised a few questions in class. The short answer was that the small amount of coffee grounds added to compost or soil was only a short term response. Soil structure and composition developed over thousands of years and what we do is merely short term. That makes sense to me.
I've posed similar questions to the professors in the biology department and not one of them can provide an answer. They suggest going to the geology department and ask there. Trouble is, we don't have a soil science expert on campus. Geology profs say they use MSU for soil analysis. It seems to me that there should be more interaction between the disciplines of science. Perhaps some day.
For now, a soil test is less than $20 from your Extension office. Or if folks like, I can get soil pH metres if anyone wants to do spot tests. I can have them at Chickenstock.