It's also worth noting that there's a very real risk of this blowing up in their faces if they try to actually act as if a clause like this was legal. It's highly probable their lawyers have told them it's worth having such a claim in their policy in case of some event beyond their control, but they shouldn't count on it to protect them if they actually were to try and abuse it in any way. I mean, this is the same Greybox who spent 6 months arguing that maintenance was here to stay, so I wouldn't necessarily count on them paying attention to good advice. Good luck on not needing to fight that particular battle, I guess? Even if the law is blatantly on your side, it wouldn't be a fun case to be part of.