Well preparing intervaltraining is quite a boring thing to do, (especially since you still have to do it in the watch instead of in STGym.) If you could upload your prepared intervalprograms to STGym then you would get two advantages.
1. Since everything is deleted when you update firmware you could just put the intervals back in the watch instead of having to recreate them in the watch.
2. If you can upload them to STGym you can also share them with other users which can be a fun thing to do. Especially if STGym is going to the cloud. Then you could set up a sharingforum there. :-)