I'm going to let product management know about this and someone will get back to you.
You should be able to create a custom report based on the IPAM events log that will show you when something about an IP changes. I know this isn't exactly what you're looking for, but the data is there and you can access it a number of ways via custom reports. I like your suggestion though; right-clicking on an IP and getting historical information on that IP would be very useful. I've logged this as a feature request.