Can someone explain the redundancies to me? If you can't text rot13("shpx") then why do they need to block rot13("shpx") + " you"? Or does that imply that rot

Can someone explain the redundancies to me? If you can't text rot13("shpx") then why do they need to block rot13("shpx") + " you"? Or does that imply that rot13("shpx") + " u" would be accepted (it's not on the list)? Or did someone just not understand how longer strings match faster?