I don’t think it would be required and it could be confusing to send a rate change notice if the rate isn’t changing. 1026.20(c) states:
Rate adjustments with a corresponding change in payment. The creditor, assignee, or servicer of an adjustable-rate mortgage shall provide consumers with disclosures, as described in this paragraph (c), in connection with the adjustment of interest rates pursuant to the loan contract that results in a corresponding adjustment to the payment. To the extent that other provisions of this subpart C govern the disclosures required by this paragraph (c), those provisions apply to assignees and servicers as well as to creditors. The disclosures required by this paragraph (c) also shall be provided for an interest rate adjustment resulting from the conversion of an adjustable-rate mortgage to a fixed-rate transaction, if that interest rate adjustment results in a corresponding payment change.