The destructuring of array with the reference on noexistent element of array = Creation an element in the array.
PHP 8.1.9 (cli) (built: Aug 2 2022 14:17:26) (ZTS Visual C++ 2019 x64) Copyright (c) The PHP Group Zend Engine v4.1.9, Copyright (c) Zend Technologies with Xdebug v3.1.4, Copyright (c) 2002-2022, by Derick Rethans
$arr = [1];
/* > CHECK */
echo 'Before change:';
echo PHP_EOL;
echo 'arr: ';
\print_r($arr);
echo PHP_EOL;
/* < CHECK */
// destructuring
[&$a, &$b] = $arr; // OK
// BUT
//[&$a, $b] = $arr; // Warning: Undefined array key 1
$b = 'insertNewDataInArray';
/* > CHECK */
echo 'After change:';
echo PHP_EOL;
echo 'arr: ';
\print_r($arr);
echo PHP_EOL;
/* < CHECK */
Bug or feature?