Including a note to reviewers in a submission
When resubmitting a paper after rejection, many journals require the authors to provide a detailed response to reviewers, whether or not the paper is going to be assessed by the same reviewers.

Therefore, instead of including a note to explain the change, include a complete response to reviewers, even though the journal you are submitting to does not require it. It would be useful even if the reviewers are not the same, because it's quite likely that new reviewers will receive the initial comments.