Originally Posted by corporate-wage-slave

Yes, BA wil rebook you to either the next day (probably the default) or to a same day service on El Al / Lufthansa if necessary. You may be in the frame for EC261 compensation, depending on the cause, though note that with short connections the risk of (e.g.) bad weather causing the irrop is that much higher and there is no compensation for that. For the final point, the usual time you will find out about rebooking is on the BA app when about an hour from landing, so use the wifi to check that, or check on landing. But if it's a complex ticket or not owned by BA, then you get rebooked at Flight Connections, there is a service desk on the right side of the hall. The self service machines are also available, but I've not yet had conclusive proof that they do anything that the App doesn't do.