Disabling revamp means that we also set expanded to false. However, since revamp is disabled, these changes are not reflected back to sidebar-main, resulting in a weird mismatch between SidebarState and what the launcher sees.
This was partially fixed by the lines in initializeState(), which updates the tab container, but not the launcher. This generalizes the solution to ensure that *all* components are kept up to date.
Differential Revision: https://phabricator.services.mozilla.com/D236240
1294445e6e