This makes sense, of course there will be contingency plans, up to and including shutting down the airport and rerouting flights like your sibling mentioned.
> Not sure about this airport, but in some (most?) places with a tower, there is a very low tech contingency where the airport can operate from a hut on the ground. Everything could be done visually plus a handheld radio and would obviously be slower, but it's there in case the tower had to be evacuated, or similar.
I think this highlights my point, since the airport itself is now "unmanned" in the sense that there is no one there to do the "legacy" way of visual controlling. This means that the analog fallback scenario is not an option anymore, which could be of small importance if it was not used a lot anyway before actually falling further back to other options.