No, they don't put your application back at the end of the line if they ask you to re-do a form or even if they return the entire application. Others have had this happen and their file was dealt with again as soon as it was returned to CPC-M. There was an applicant in Feb via London whose application was returned to him in March, he clarified the matter they mentioned, and returned his application in early April, and he had sponsor approval shortly thereafter. He has actually received his PR now.
However...having said all that, that happened BEFORE this current backlog CPC-M is dealing with. Once again, SOME June applicants, like yourself, STILL DO NOT HAVE SPONSOR APPROVAL YET. You are not at the back of the line, but neither is your processing complete, apparently.
Either you wait for CPC-M to send you the letter, or you can try calling the Call Centre to find out if they are making any progress.