Facebook translations are crowdsourced. Doesn't excuse this particular case, but don't assume it was anything malicious on Facebook's part.
This is the correct answer. Someone accepted the translation without thinking too much about it, but it's almost certain that it wasn't a Facebook employee who decided on that "translation".
They seem to have changed it already. It's "F3m413" for female and "Male" for male now.
So you switch to a novelty translation yet have no sense of humor?
Granted it's in bad taste, but... it's fucking 1337 speak.
So what does it substitute for various races? And what's the "male" leet-speak equivalent?