I noticed that while I was developing the script. I'm using annyang -- https://github.com/TalAter/annyang -- to interact with the web speech API, and it doesn't look like annyang is the one censoring the results, so it must be ... the API itself?
That is unbelievably messed up. The fear of swear words in american culture actually messing with APIs. I really hope this isn't what it looks like and someone is playing a prank somewhere.