Besides the compact shared between many states which was only set up to ensure people paid their out of state tickets. All states now share DMV records with a central database, Even though the op has a valid CA license at presents and Valid OR license, once and if OR suspends that license they will report this suspension to the shared database. Now if the op never clears the matter with OR this suspension will stay in affect. If at some point in the future CA check this database and you know they will and sees that the op has a valid suspension in OR they will in put a hold on his CA license, they may even suspend it as well until he clear the matter with OR.
Unlike 10 yrs ago when people could move around and their records or bad behavior did not follow them easily it is not the case anymore. CA will at some point find out about the OR suspension and will take some sort of action.
The simplest thing will be that CA notifies you of the outstanding suspension and makes you clear the matter with OR the worse will be you get pulled over and the officer runs a check and it comes back you driving on and out of state suspended license and they haul you in.
There are plenty of examples on this forum where people thought a suspension would not catch up to them in a new state, is not the case anymore welcome to the modern age of information systems and data mining which the government has gotten very good at.