No.

And I'm not sure if this is something we'll want to support either. Being able to edit everything is indeed "the wiki way" but technically implementing that is not trivial here, as we'd need at least one new DB table (probably more) for storing the edit history and whatnot.

Somewhat related: T156736: Comments should implement a history interface (the MediaWiki-extensions-Comments extension)

@SamanthaNguyen, what do you think?

I see. I just asked because if someone is not able to edit their own messages then they aren't able to fix any mistakes they made in their message, and also I thought maybe this would be added considering editing ones own comments is a pretty widely used feature everywhere. But if it's too much work then oh well.

Btw couldn't you able to utilize the Flow extension for the boards somehow? I'm not sure if that would make things easier or make them even more complicated.