Indeed. What's more, even if publishers wanted this, it's all possible without a blockchain. If game publishers decided to coordinate on respecting shared digital assets they could just agree on a common "digital item" spec where a connected client could prove item ownership using public key cryptography and digital signatures, similar to how JWTs let a client prove claims about another system. The same spec could allow users to trade digital assets in a peer to peer manner by signing a record of transfer to another user's public key - it'd then be up to the buyer (i.e. the software they use to verify the signing) to register the updated signature chain with the relevant game vendors.