Maybe the level to which it's all intertwined is exaggerated, but certainly the 2012 parcours was one extremely favourable to Wiggins, even before we knew he was on super-form, just as the 2009 parcours, seeing the return of the TTT and neutering the first set of mountains, was designed to keep Armstrong in contention as long as possible for the audience, even before we knew what kind of performance level he was at.
At my most conspiratorial, I always marvel at how interestingly the development of British cycling coincides with the decline of German cycling, a comparable (if slightly larger) population base with a strong pseudo-national team (replacing the German audience with, say, a Czech one, would not do since the potential audience from the Czech Republic is far smaller), and a cycling structure which had produced a lot of riders and money for about 15 years yet was almost totally dismantled within one or two. There's a year or so between the fall of T-Mobile and when the British riders started to be really noticeable, beginning with Cavendish winning 4 stages in 2008. I often wonder if the UCI, ASO or both noticed that there were quite a few young British riders with potential at that time and thought that they might be able to develop an audience to replace the lost audience figures in Germany when they pulled the plug if those guys went the right way, and with this Cavendish guy showing a hell of a talent for sprinting, that might be a catalyst they could use.
But then, if coverage is still hidden away on a minority channel then did it really work? I mean, British Cycling's profile is undoubtedly a lot, lot higher than it was, but while Wiggins' name value is high, I'd expect that the likes of Hoy and Pendleton still have far more name recognition than Froome in the UK. The British Olympic Committee have admitted they isolated cycling as an area to put a lot of funding in because there were a lot of medals available in a shallow field of competition. Having brought all the success to that, it only made logical sense, once all targets were achieved on that front, which they were at Beijing, to move into the road, since that's where the international money in cycling is to be found.
I don't think it's all intertwined, it's two coincidental strands (Britain looking for success, funding cycling, moving into road cycling, trying to develop interest in the sport beyond the Olympics is one; ASO/UCI looking for a new market to replace lost audience and races is another). If Britain hadn't put that funding in WHEN they did, or if they hadn't chanced upon a world class athlete like Cav at the time they did, maybe it would be different, and the coincidence with the London Olympics is perhaps just that - a coincidence, although it may help understand why the progression has been so quick and why the course at the 2012 Tour was so suited to the British contender. Remember, we've seen the revamping of the points classification at the Tour to make it easier for Cavendish to win, we've had one utterly pancake flat World Championships, we've had a series of sprint- and TT-heavy parcours in recent years that suit the kind of athletes produced by a track program.
There is stage managing out there for sure, but there's also coincidence.