Seeing a nice discussion on Email Geeks Slack community trying to figure out whether Gmail is finally going to support prefers-color-scheme media query because a Google engineer marked this issue as fixed.

We all want this to happen. Though naturally developers begin to question consequences "what happens to my current templates that use Gmail-targetted dark mode hacks?"

Reality is, positive change in how email clients render HTML emails require the introduction of breaking changes. The lack of standards made it so. There is no way around that.

We at Email Markup Consortium discussed this previously: enforce standards, introduce breaking changes to set the foundation for the future, and provide a reading mode within the email client to allow the users to consume broken emails. Read more about Backward compatibility in email on the Email Markup Consortium blog.