Found my stolen iPhone - now it is unavailable
We had an iPhone 12 Pro stolen and then we managed to get it back. The screen still says "iPhone Unavailable" and our only options are Emergency or Erase iPhone. We've tried in iCloud or Find My but can't do anything there. Reading other posts it seems like the person tried repeatedly to get in or tamper with it so due to its security features the only option now is to Erase iPhone.
Can someone give me some guidance about what steps to take from here? What will happen if we select Erase iPhone? We're okay with it being reset and losing the media and data on the phone but are unsure what steps will be taken if we choose to erase it. I assume it will still be somehow connected to our Apple ID or original phone password. Otherwise the thief could have simply erased it and started from scratch.
iPhone 12 Pro