It all depends on what type of tickets you purchased last year and whether tickets were purchased when you booked for this year.
If your tickets form last year are NOT Ulitmate Park Hoppers, you will be able to use them this year. Not a problem at all.
When you booked for this year, you booked a "Room Only" package which is just that. Tickets are not included. Your DH co-worker probably booked with tickets and in that case, they are placed on the room keys. You may want to double check you have a "Room Only" reservation. If you do have a reservation which does includes tickets, you may have time to switch it.