True

The tab state is controlled either by a hash in the url or an attribute in the tabs element

JHtmlBehavior::tabstate() is empty in 4.0. Should it be deprecated/removed?

The "problem" is that while the opened state works ie when you return to a page you are on the same tab what doesnt work is the ability to open a tab directly with a link eg administrator/index.php?option=com_config#page-permissions

TypeError: tabLink is null

    showTab(tab) {
      const tabLink = document.querySelector(`#tab-${tab.id}`);
      tabLink.click();
    }