Originally Posted by corporate-wage-slave

This isn't an EC261 issue, so we are off to BA's policies. Certainly in the past YouFirst has been willing to look at moving flights when First is cancelled, using commercial space if needed. There is a specific policy that covers this if your flight gets cancelled, and there is a big chance this will happen to one or both legs, but custom/practice has been to allow this. But there are all sorts of complexities here - this isn't a route where First can be guaranteed, what if there are further travel restrictions, what if BA changes policies, or even drops the route? So personally I would only move flights if you were sure you would be travelling, and if not it would be better to wait and see what happens. If you enter into a dialogue with BA on this too soon, you may find yourself boxed in by the available options.