Couldn't Satoshi think of some system to report for coins that haven't moved more than a certain amount of time so they get flagged by completely inactive and lost? Just talking from the top of my head here.
I highly doubt it would be accurate. Afterall, those coins rightfully belongs to the owner of the BTC address. It isn't right to reclaim it. Moreover, people can easily use those address as cold storage and not have any transactions with it for extended period of time.
If those wallets are deleted and coins are sent to it, the coins will be gone forever. They can't be reclaimed without a fork but majority of the community probably wouldn't agree to this. To spend those coins, you definitely need the private key. Without it, the nodes would consider it as invalid unless the transactions are signed with an ECDSA signature of the private key.