I'll await your retraction. ;-)
But by the late '90s, that standard had been steadily eroded by altogether shaving off clearance time, lowering yellow light intervals by as much as a third, which often leaves the motorist stranded in the dilemma zone.
The article in question had one glaring omission in this discussion of historical changes in the recommended yellow intervals. The reduction of the yellow interval was accompanied by the introduction of a new type of signal phase that had not been used previously: the "all-red" phase in which no traffic is permitted to enter the intersection. You can go to any intersection today and time this yourself -- the length of the yellow interval plus the length of the "all-red" interval falls well within the 3-second to 6-second "yellow" standard that had been used previously. In fact, I don't think I've ever come across a "yellow + all-red" phase that has been less than five seconds in length. The least expensive way to reduce right-angle accidents at signalized intersections is not to extend the yellow phase, but to add an "all-red" phase that will (in theory) provide a brief interval of time between changes in vehicle right-of-way. I use the term "in theory" because motorists eventually get attuned to these signal timing changes and start using the all-red phase as an extension of the yellow phase.
According to Section 4B-15 of the FHWA's Manual on Uniform Traffic Control Devices, "yellow vehicle change intervals should have a range of approximately 3 to 6 seonds." So we know that this hasn't changed.