Really good question. I asked my 19 yr old son who has an xbox and plays nearly every day, and what he said was no, the "last played/used" data isn't actually stored (that he's aware of), it just shows
what was last played, and that your friends can see when you were online last. That would be helpful, except he said as soon as the console is turned on, the "last seen online" would update to right then, as soon as it was turned on (if that makes sense).
Xbox support says this: "Your data is stored on both your hard drive and in the cloud. Xbox Live keeps your important data in sync so you don't lose anything when you use a friend or family member's console, or even when you switch to a new console."
https://beta.support.xbox.com/help/games-apps/game-setup-and-play/cloud-game-saves-faq
So the hard drive/cloud would show when the last time the data was synced if you could access it without actually accessing it from the user account (because then it would just sync and say last synced - right now).