This has been detailed by dataminer 'OatmealDome' on social media, who once again mentions how these updates "do not require the console to be restarted and often contain minor changes". This latest build has (you guessed it) updated the "bad words list". We won't go into specific details but it appears to block a "censor-evading way" to write a certain word in Japanese.
The original 18.1.0 update for Switch was tied to the discontinuation of X (formerly Twitter) integration and some features linked to games like Smash Bros. and the Splatoon series. The same update also included some "general system stability improvements" to enhance the overall user experience.
