Allow Subscribers in User Profile Picture and Gutenberg

allow-subscribers-user-profile-picture-gutenberg.php

<?php
// For User Profile Picture
add_filter( 'mpp_gutenberg_user_role', function( $role ) {
	return 'subscribers';
} );

// For Gutenberg
add_filter( 'rest_user_query', function( $args, $r ) {
	if( isset( $args['who'] ) && 'authors' == $args['who'] ) {
		$args['who'] = 'subscribers';
	}
	return $args;
}, 10, 2 );