If a procedure is rolled back, will the result of the trigger (AFTER INSERT) that was fired within this procedure be preserved?

If the procedure within which the AFTER INSERT trigger was activated is rolled back (ROLLBACK), then all changes made by this procedure and trigger are also canceled. The trigger executes within the same transaction context as the procedure, so its actions will not be saved if the transaction is rolled back.

That is, the result of the AFTER INSERT trigger will not be saved if the procedure is rolled back, because all changes within a transaction are atomic and either committed together or rolled back together.