The answer is that it is not required. Putting it there can provide the disclosure early, but it is difficult to ensure it was in fact reviewed and it can increase site maintenance if you change it.
It doesn't hurt, and it helps only a little. But you cannot rely on this for your customer notice without checks and balances.
My opinions are not necessarily my employers.
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell