Correct.
This situation has happened recently where a shorter (required) Resort Package ticket was first upgraded to a 10-day ticket (and the ticket WAS price-bridged at that time) but the ticket was still never used at all. (The guest was actually using a current AP during that same trip.)
But, then, on the NEXT trip, the guest wanted to use that previously-upgraded 10 day ticket to help pay for a new AP.
There had been a ticket price increase during the interim time.
The guest wanted that 10-day ticket to be price-bridged (a second time) before it was upgraded to an AP.
Since that 10-day ticket had already been price-bridged once, it was no longer considered to be the original Resort Package ticket, and was not eligible to be price-bridged at the time of the AP upgrade.
(Incidentally, in the above case, the guest WAS given one-time-only "pixie dust" and was allowed the second price-bridging by a WDW manager.)