"chat" event is emitted when commands are run.

[BF5258]

• The FAQ doesn't contain a resolution to my issue

Versions

• mineflayer: 4.20.1
• server: vanilla 1.20.4
• node: 20.15.1

Steps to reproduce

bot.on('chat', (username, message) => { console.log(username); console.log(message) }
Connect to the same server as the bot.
Run any command. I ran \give andy stick 2. (andy was the name of the bot)

Observed behavior

The following was logged in console:

BF5258
Gave 2 [stick] to andy]

Expected behavior

Nothing should be logged in console. The 'chat' event should not be triggered. No one has chatted.
If this is intended behavior, why don't command blocks emit the same message?

Additional context

When the command is run the following system message is sent:
[BF5258: Gave 2 [stick] to andy]
The regular expression used to detect chat catches this despite it being in square brackets.
The expression used: /^(?:\(.{1,15}\)|\[.{1,15}\]|.){0,5}?(\w+)\s?[>:\-»\]\)~]+\s(.*)$

mineflayer\lib\plugins\chat.js line 3,4:

const USERNAME_REGEX = '(?:\\(.{1,15}\\)|\\[.{1,15}\\]|.){0,5}?(\\w+)'
const LEGACY_VANILLA_CHAT_REGEX = new RegExp(`^${USERNAME_REGEX}\\s?[>:\\-»\\]\\)~]+\\s(.*)$`)

Solutions include changing USERNAME_REGEX to not match the square brackets or ignoring 'chat.type.admin' messages.
Why does the username regex have wildcards on the start and end?