JQueryのデータセレクタが.dataで更新されない

var howMany = $('.t[data-test="test"]').length;
$('.result').html('start there are ' + howMany + ' divs with data "test"<br /><br />');
setTimeout(function() {
  $('#one, #three').data('test', 'changed');
}, 500);
setTimeout(function() {
  var test = $('.t[data-test="test"]').length,
    changed = $('.t[data-test="changed"]').length;
  $('.result').append('there are ' + test + ' divs still with data "test"<br /><br />there are ' + changed + ' divs still with data "changed"<br /><br />');
}, 1000);
setTimeout(function() {
  $('.t').each(function() {
    $('.result').append('div #' + $(this).attr('id') + ' has the test data of: ' + $(this).data('test') + '<br /><br />');
  });
}, 1500);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="t" id="one" data-test="test">1</div>
<div class="t" id="two" data-test="test">2</div>
<div class="t" id="three" data-test="test">3</div>
<div class="t" id="four" data-test="test">4</div>
<div class="result"></div>