Keep in mind that his context is automobiles and/or heavy machinery. These things typically have much higher loads and higher RPMs than do bicycle bearings. A bicycle wheel is going to see a few hundred RPM. A 700c spins at about 750 RPM at 60 mph. So typical wheel spin will fall between 100 and 325 RPM. A bicycle bottom bracket might see a bit over 100 RPM every now and then. There won't be much centrifugal action working on the grease. I did take your post seriously and did some searches on moly grease with ball bearings. And the main issue seems to be with high speeds. If we consider the U-joints the engineer mentions, we will notice that these spin typically in the thousands or RPMs under much higher loads. Also, Ford specifies a moly grease for at least some of the wheel bearings on their cars/trucks. The Valvoline moly grease calls out that they "Meet Ford Specs." I wouldn't worry one bit about moly creating problems in bicycle bearings.I'd bet if you asked this engineer he'd agree. I'd also bet that he'd say that moly grease is unnecessary for most bicycle applications and probably only provides some benefit in applications like coaster and/or roller brakes.

After all, what he said was, "One can never go wrong using a high quality non-moly grease in every application ..." which was my main point.