I've never had a TS3 store world disc in my own hands to be honest. Actually, I've never had any TS3 discs in my own hands as my installs have always been digital. But I'm almost positive that regardless of what those instructions say the disc doesn't really do anything for you except allow you to have spent your money in a retail store (or wherever) rather than through Origin or the origin.com website either of which would in that case be acting as purchasing agents only.
No one should need to repurchase store content, including worlds, if they are continuing to use the same store account and login credentials. Redownload, maybe although even that shouldn't be necessary for an Origin to disc install crossover.
