The AirPods case can already be tracked, but annoyingly you can't make it make a sound. If you leave a single AirPod out, you can make it make a sound, but for me this is useless because I always misplace the case (with AirPods inside). I don't see why it's not possible to have the AirPods make noise from within the case. I understand the sound would be muffled by the case itself, but that's still better than nothing!

Can they be tracked? Every time I try, the map location is seriously out of date

Instructions here: https://support.apple.com/en-us/HT207581