The transfer does not include the private key for the address, so how can it be claimed that ownership of the address has been transferred? Furthermore, even if the private key is also transmitted, then ownership is only shared and not transferred because the previous owner still has the private key.
In this 'NFT' project we call it 'ownership'. First, only the owner of the initial address is the 'owner'. If they sign a message where the message is the Bitcoin address of the new owner and sends from the their Bitcoin address coins to the new owners address (the message in the signature) then the holder/owner of the private key of this address is the new owner.
This works only if the initial owner signs a message and sends BTC to the new address. Then the 'ownership' isn't shared as another signature of the previous owner to another address + transaction to this address wouldn't be accepted by the participants as the rules are: the first transaction on the blockchain from an address is valid. All transactions thereafter don't count, are valueless. (We will have a initial block number, whereafter this will be valid.)
I know, it is a bit difficult to understand/explain because we don't have examples on the blockchain but they're on their way. To explain blockchain was difficult too, but once understood and saw it working, people got it.