That’s not exactly related to this, we removed a couple of items from the toolbar prior to adding the toggle, and the toolbar was already wrapping before.
Specifically on Meta, though, I’m not sure how useful is the writing direction toolbar item, especially as (at least on desktop, not sure on mobile), you can right-click and change the writing direction natively in the browser. Either way, even if enabled, it could be behind the more menu.
That said, I think we can take the exact same logic we have on mobile, where it becomes scrollable instead of wrapping, and bring it to desktop.