Possibly not...because I think they currently give you the tickets when you check in to the hotel for on-site packages. So there's no restrictions on the ticket itself but you may not physically have them until you check in to the hotel... Are you booking on-site hotels?
It's worth mentioning, though, that there's ZERO reason to book a package through Disney. There are no added benefits to doing so (other than perhaps the ability to make payments over time but there are other ways to manage that). Particularly if you are not booking one of the on-site hotels- rates are often better booking directly or through other sites.