The list of functions were added in Issue 17844. I made the change today because I forgot that the listed functions weren’t exactly equivalent when investigating Issue 25075.

Base64-codec encodes to multiple lines, but b64encode() returns the raw encoding without line breaks. I see that base64.encodebytes() is listed as a “legacy interface”, but as far as I can tell nothing outside the legacy interface does any line splitting.

Hex-codec encodes to lowercase, but b16encode() returns uppercase, following RFC 4648.

Quopri-codec encodes all whitespace, but quopri.encodestring() lets most whitespace through verbatim by default. In this case I think it would be reasonable to change back to encodestring() if we say that quotetabs=True is passed in.