As you've had only one edit suggestion rejected, it's not difficult to find the question referred to and the details of the rejected edit.
Your proposed amendment was to change:
Is there a word for someone who really has their act together
Is there a word for someone who really has his/her act together ?
You will see that it was rejected independently by two separate reviewers. Although I have not seen the edit previously, I would agree with their decision, which gives the standard wording:
This edit is too minor; suggested edits should be substantive improvements addressing multiple issues in the post.
The use of their for his/her in the question is neither "incorrect" nor "controversial". The discussion of that issue in numerous previous questions on the site show that the usage is long-established, frequently used, understood and accepted.
[Disclaimer: That statement is made from memory: I have not checked previous questions at this time.]
My personal view is that short edits on question titles should be made where necessary for clarity, but, in this particular case, the suggested edit was both unnecessary and trivial.