I think that a game has to be “purchaseable” for $0 to have a “claim” option. If it’s just “free”, it won’t have a “claim” option. Some authors seem to switch this setting on purpose to stop people from keeping free download access to their game after the free period has ended. Sure, we could just keep the files backed up ourselves, but a) how many people really do that, and b) the author could release updates and DLC later to encourage a purchase.