I am just wondering why he suddenly decided to make it a "story". he knew about his condition for two years and so did his team. Suddenly he decided that it is time to share it in the middle of the Tour. Maybe he will win this year and his story would be special, but bringing attention to himslef this way...
I could be entirely off base with this assumption, but...

Bike racing is as much mental as it is physical. The weekly RoadBikeRider e-newsletter recently had an article about psyching out your opponent. Floyd seems to be a smart guy. It wouldn't surprise me a bit if he timed this announcement strategically to psyche out his fellow Tour riders. Kind of like saying "You think you're tough enough to beat me? Look at what I've been dealing with! Bring it!!"

Some folks might find that offensive but, personally, I think it's pretty darned cunning.