Years ago, I recall when two constituent records were merged a note would automatically populate to the record.  I asked and was told it no longer is available.  This is essential tool especially when you a de-duping records.

It used to have the wording ie

#22222 Smith, John merged into #222223 Smith John E.

I attached a sample of the conversion note that automatically generated when converted individual to organization.  Which is similar to the note that you use generate when two (2) records were merged.