My recollection (and it's been a year since I was
head-down in the DB
tables, so it may be wrong) is that the Database stores all the
changes by user ID not username - so, if you change an IDs associated
name (the usurped account being renamed) then the ownership / change
history changes along with it transparently.
True, but not relevant. They go from being attributed to the name you
chose to being attributed to some other name, that's not preserving
the section entitled "History".