Adding a line to an Active Service Contract requires approval again?

If an Active Service Contract is opened for update and a change is made like adding a billing contact on a line, on running the QA Check the contract goes back to Active Status on passing the QA check. However if on an Active contract, I open for update and add a new line, the successful QA Check does not send the contract back to Active status, it stays in QA Hold status. Do we need to submit this contract through approval again? If yes, in what all cases of updates is such approval required? I could not find any