30 minutes is way too short. 90 minutes is a good starting point. At least make it as long as a typical meeting + time to download any final notes after the hour is complete.
Soy milk is absolutely not a requirement of any diet. In the scheme of human diet, it is a relatively new invention, so it absolutely cannot be a necessary staple of human diet.
Can the body process it? Sure. But your body can digest almost everything.
These sorts of "studies" are still being published, many of them funded by the dairy industry. Has nothing to do with science or nutrition as is taught in college, it is simply sales and marketing not unlike similar studies done by the tobacco industry just a few decades ago.
It is in fact old, however I hadn't seen it posted anywhere even back then, figured I'd pass it in since there was some speculation about the feasibility of such an attack given the spike in Tor client usage.