No, they did not, they present both "accessible hidden link" and "inaccessible visible label", at least I see no `aria-hidden="true"` in the code [1] on the label right now, I see just:

    <label for="menustate">
      <span class="open">≡</span>
      <span class="close">×</span>
    </label>

So there still remains "readable" structure loosely identical to

    <label>identical to multiplication sign</label>

(With active CSS, only one half would be presented to SR, since the other has `display: none`, but still…)

BTW Fact that wording of the link in the article pointing to the codepen is "this codepen" is also … not right.

[1] https://codepen.io/enyo/pen/yLqjrOR