I will start off by saying that there are much more important things that the devs have to worry about than this suggestion (my fellow recipe collectors will understand my sentiment, however).
It was very convenient when the WotLK cooking tokens could also be used for the Cata recipes, and vice versa, allowing players to collect all of the recipes and the cooking hat in half the time. This was also done when all of the different types of points were combined into one type of currency at the end of WotLK, and also when the battleground marks were just turned into honor points.
I would love to see this done with the jewelcrafting tokens. Again, not an extremely relevant change, but something I know collectors going after JC recipes would love to see. Just my .02