This bug has been filed several times:

issue1257
issue11654

and it's tempting to simply close this as a dup, but this ticket mentions the documentation, which is slightly confusing: 

https://docs.python.org/3.8/library/atexit.html#atexit.register

It's not *wrong* exactly; 3.8's behavior matches the letter of the documentation, but "the last exception to be raised is re-raised" *implies* a change in exit code, since that is what would normally happen if an exception were re-raised at the top level.

So would it be a good idea to change the documentation?