I certainly agree with the first sentence. The second, I'm less certain. The issue with having bigger glycogen reserves isn't just about the first couple of hours, is it? As we discussed earlier, one can't replace calories as fast as one burns them - if one is riding at RAAM speeds one is probably chewing through 600-800 kcal per hour, and one can only absorb 250 or so. Now, most of the calories burned will come direct from fat stores, so the issue is whether one's intake of 250kcal per hour of carbs is enough to replace the relatively small amount of glycogen consumed. It will vary with intensity, of course, but in a true endurance event it might be pretty close, and one's glycogen reserves may be depleted only very gradually. So starting with a bigger reservoir may allow one to ride at a slightly higher intensity throughout and still make it to the finish.

The theory seems plausible, anyway. Whether it can be managed practically is another matter.