I worked in the semiconductor industry for 5 years before going to law school. This is a somewhat common practice; it isn't something to be alarmed about. One of my previous employers had a similar issue -a significant number of chips that had higher leakage than the spec would allow for mobile applications. They also packaged these chips up for use in desktop, always plugged in applications. Certain portions of the wafer and certain lots of wafers bin out higher than others at probe, this is the reality of semiconductor manufacturing. In many ways, this is no different than how processor speed grades get binned out, i.e., they don't design a 2.2 GHz part, a 2.4 GHz part and a 2.6 GHz part. They design a 2.6 GHz part and bin the different speed grades out.
I don't believe that there is anything to worry about as far as reliability or functionality go. These parts (if the Inquirer's assertion is even true, which is questionable based on his overt hatred for Nvidia) most likely draw an extra watt or two, which isn't a huge concern. In some ways this is a good thing, Apple probably pays a price premium for their chips (once again, if this is even true), which makes the other chips cheaper. The alternative is to throw the higher power consumption chips out, driving up the price for everyone.