The cryptocurrency is a product derived from the blockchain. Ethereum has promoted the production of cryptocurrencies, so I think Google can do this kind of work easily!
But google not did not because of that reason. They said clearly in their statement that they are not against the cryptocurrencies but the actually cannot filter the scammers in the crypto currencies that is why they are going to ban. But I think it is now allowed as we can see advertisements of cryptocurrencies on google.