No. If you are just booking a room only you can buy park tickets separately from a ticket broker. I've used
Undercover Tourist, and have been happy with their service. They mail you real tickets, not vouchers like some other sites. And their posted price includes tax. Shipping is free. So when comparing ticket prices most sites don't post the complete price with tax till you go to check out, then you find out the total price with tax, and some sites charge for shipping.
You will save a little by ordering from them, depending on what specials they have.
If you book a pkg with WDW- room + tickets, you would just order lenght of stay tickets on the first res, if your entire stay is 4 days. then on second resort res, you would book room only. Your park tickets for all your days will be on your 1st resort KTTW card.