They might better attach a plaque stating the detailed historical context. Most people would probably get so bored after reading the first couple of sentences that they'd shrug off their uninformed objections and walk away. Those of us who would be interested would read it, then head for the library for a deep dive into the history. Either way, the history and its effects happened and can't be undone, but if the evidence is obliterated there's danger of believing that the resulting societal ills have been repaired when they've only been swept under the rug.