if i create a new address now, as far as the network is concerned since it never was online who's to say what the right key is?
tell you who, my wallet (or the private key within).
it's not that your node broadcasts every new address you create to the network, why should it?
there's no need to inform the network about new addresses, your node only needs to check, if that address has ever received some coins
and if you've got the (private) key to those coins, you can spend them.
one could claim unused
addresses, one could also claim all lost coins that he/she knows the public key of, that person could get rich without actually stealing
anything from anyone.