Mojang can’t really act on guidelines unless clarified. Players can’t be reported to mojang unless messages are cryptographically signed and there’s an actual report system.
Even if the rules are not enforced, they’re still there. They’re stupid and should not exist. Minecraft is a game for all ages, and it warns you very clearly when you go into the multiplayer section that content you may find there is not controlled by or affiliated with microsoft and when you join a server you join it at your own risk and if necessary with consent from your parent or guardian.