WDT was already super popular, so the declumping properties aren't very useful. And the static issue is mostly limited to non-traditional light roasts.
Is this the same when you try to mix coco powder with milk? You need to first use a little bit of milk or water to get it to form a sauce. After that you can easily mix it with milk
I am not a coffee historian or even very knowledgable, but I thought that light roasting is the more traditional (even ancient) way of making coffee and that the roasting has gotten darker over time. Not so?
"Ancient" coffee roasting was probably very uneven. The beans were often just roasted in a skillet over a fire, not unlike toasting pine nuts. If you've ever tried toasting pine nuts on a stove, you've gotta be very careful with the heat control and keep the nuts moving frequently, or else you'll have some that are still blonde and some that are bordering on burnt.
It says in the linked article that darker roasts have less internal moisture content (obviously, they've been roasted longer) and therefore produce more static/clumping.
WDT would be an extremely obvious thing to test in both the original paper as well as the follow-up videos by Hoffman/Hedrick. It is absent in all three.
Also note that Hoffman found RDT only helped in _some_ grinders. WDT also only helps with some grinders.