Thanks for that link. The article is a little long-winded, but it is well researched. Note that it does identify flexibility as one of the few things that stretching actually has been clinically shown to improve. Whether one needs more flexibility for cycling is very dependent on the individual. If you're happy with your position on the bike, stretching may not offer much benefit. But it also won't hurt and it does feel good (when done properly) so I wouldn't dismiss it without trying it.