This is good news for the internet. PKI and TLS are the foundation of trust on the internet. But in the past issuers could get away with poor practices because none of the major browsers wanted to lose market share by “breaking” websites.
Trust of the internet is a far more important to Google than browser market. They’ve also correctly anticipated that the internet community takes security more seriously now than they did during the IE vs Firefox browser wars.
Mozilla, to its credit, has followed Googles lead generally and occasionally takes on a more strict interpretation in some instances.