FTA:

> What changes with the return of Chat Control 1.0—and what stays the same:

> What is coming back: US tech companies are once again allowed to scan private messages without a warrant or prior suspicion. This affects direct messages on platforms like Instagram, Discord, Snapchat, Skype, and Xbox, as well as emails via Google’s Gmail and Apple’s iCloud.

> What remains unchanged: Public social media posts and files hosted in cloud storage could already be scanned without this law. Furthermore, private messages can always be reported by users, or monitored by authorities using targeted, court-ordered wiretapping.

> What is still NOT being scanned: End-to-end encrypted chats, such as those on WhatsApp, have always been exempt from these scans. Additionally, European providers of messaging and email services have never implemented chat control measures.

As far as I understand this. It basically gives the company providing chat services the possibility to scan your messages.