When marking a page for translation, sometimes the page itself needs to be modified (e.g. to add translation unit markers). This edit is made on behalf of the translation admin, a human, but it’s marked as a bot edit (in contrast to edits to translations, which are made on behalf of FuzzyBot, and are rightfully marked as bot edits). Marking human edits as bot edits is confusing, and doesn’t seem to be necessary, as such edits are not that frequent. I think edits made on behalf of translation admins should not be marked as bot edits.

Historical/technical notes

Special:PageTranslation was introduced in rETRA819b34d8d0ae3ff4fcbcf106d06db715d9b9e776 (then tag/SpecialPageTranslation.php, now src/PageTranslation/PageTranslationSpecialPage.php), and ever since these human edits had the flags EDIT_FORCE_BOT | EDIT_UPDATE. In that commit, a similar code was removed from tag/FuzzyJob.php, but in the removed code $wgUser was FuzzyBot, while in the new code, $wgUser is the human user (translation admin). Thus this may have been a copy-paste error. (@Nikerabbit, any chance you remember? It was over thirteen years ago…)