This recipe removes the default PMPro Cancel on Next Payment date email message and adds the !!access_expire_date!! email shortcode for the Email Templates Admin Editor.

cancel-on-next-payment-date-expiration-date-email-variable.php

<?php
/**
 * This recipe removes the cancel email filter for Cancel on Next Payment Date
 * and creates the shortcode !!access_expire_date!! that can be used in the
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

 // Only remove filter if Email Templates Editor is active
function remove_pmproconpd_email_filter_for_cancel_email() {
	if ( function_exists( 'pmproconpd_pmpro_before_change_membership_level' ) && function_exists( 'pmproet_email_data' ) ) {
		remove_filter( 'pmpro_email_body', 'pmproconpd_pmpro_email_body' );
	}
}
add_action( 'init', 'remove_pmproconpd_email_filter_for_cancel_email' );


// Creates !!access_expire_date!! that can be used in email template
function my_pmproet_pmproconpd_access_expire_date( $data, $email ) {

	if ( function_exists( 'pmproconpd_pmpro_before_change_membership_level' ) ) {
		global $pmpro_next_payment_timestamp;

		// Only filter the 'cancel' template and
		if ( 'cancel' === $email->template && ! empty( $pmpro_next_payment_timestamp ) ) {
			// Get user object
			$euser = get_user_by( 'email', $email->email );

			if ( ! empty( $euser ) ) {
				// Is the date in the future?
				if ( $pmpro_next_payment_timestamp - current_time( 'timestamp' ) > 0 ) {
					$expiry_date = date_i18n( get_option( 'date_format' ), $pmpro_next_payment_timestamp );
				}
			}
		}
	}

	if ( ! $expiry_date ) {
		$data['access_expire_date'] = ''; // set default if no data available for next payment timestamp
	} else {
		$data['access_expire_date'] = $expiry_date;
	}

	return $data;
}
add_filter( 'pmpro_email_data', 'my_pmproet_pmproconpd_access_expire_date', 10, 2 );