English has Rules, Just Like Japanese!

[Mhaeric]

It may also be relevant to note how Merriam-Webster's editors decide what to put in the dictionary



This means there isn't a magic judge of all things arbitrarily deciding to "make changes to the English language". MW adds words to the dictionary when the words have enough staying power, demonstrated by both recent and extended widespread use from a variety of sources.

They're not changing our language; they're documenting how our language naturally changes with society.

Which in this case, the use of the word they in a singular sense has been around since roughly the 1300s. The use of word they to refer to someone who identifies as gender non-binary has been documented as early as the 1950s and likely was used long before that since we have been naturally using the singular form of it for centuries. Both are considered correct English.