So it turns out we had an old board template in our account which has a fullscreen timeline view in it. It seems that if you have an old one you can duplicate the template and create new boards with the full screen view, they just don’t let you add a fullscreen timeline view anymore but haven’t taken it away from legacy users who had it. If you really really really want this you can DM me on here and I could clone the template + copy to your account. To do so, you’d have to make me an admin on your account temporarily (or create a temporary shell account) in order to use the cross account board transfer tool, so this is a bit time consuming.