The point with that line, is that the moderators will not expect or demand that you educate others on your heritage or other matters of importance or sensitivity. If you choose to do so, then that is by all means welcome and appreciated.
Sometimes it can be very exhausting and difficult for people to repeatedly educate others on something like racism or sexism (especially if they themselves have been hurt by it), and if they want or need to walk away from a discussion or argument, that is entirely their right.