Also, their FAQ says:
Q:I have received character reactivation support from the PlayOnline Information Center in the past. Am I still eligible for the service?
A:Yes. Please confirm all requirements for eligibility and apply through the application form.
Q:I deleted the character data on a Content ID before cancelling the ID itself. Can I still reactivate the character?
A:If the proper conditions are met, the character can be reactivated regardless of whether its data was deleted or not.
Q:Do I need to obtain a Content ID before applying?
A:No. You can obtain the necessary number of Content IDs after confirming how many of your characters can be reactivated.
So you'd still have to use your old content ID, but you don't need to reactivate it until after you do a restore process on your character(s).