Components also tend to build over the course of season as the program becomes grooved. Also, to assume that B/S's improvement and move to Zhulin would guarantee a leapfrog over W/P ignores the fact that the Canadians have made huge strides the last two years. Before that point the teams were roughly equal. W/P are not going to sit idly by and rest on their laurels. They have a real shot a podium finish at both Worlds and Olympics. B/S Have to not only catch them (along with the French, Shibs and Italians), but also pass them. That's no mean feat. Not saying it's impossible, just very difficult at this lat stage in the cycle. I's argue the Canadians made their move at the better time.
Plus W&P are really the #3 team at this point. No way in hell P&B stay in front of them, now that they got their retirement medal at Worlds.