I do only have this link but this is already a 2 month old news https://www.independent.co.uk/life-style/gadgets-and-tech/features/google-bitcoin-ban-cryptocurrency-adverts-ads-latest-a8376346.html.
I don't know if its really being implemented yet I do still see some crypto-ads even as of todays. Care to share on the link source regarding on such ban?