XMPP and Matrix already have WhatsApp bridges, though through they are not officially supported or accepted by WhatsApp.

Hopefully what will change now is that such bridges can be updated to use officially-supported methods, which (if WhatsApp play nice) means they will be more reliable and user-friendly than they are today.

Isn't the bigger issue that these bridges require you still to have a whatsapp account? So it's just a different frontend, but you're still bound by Meta's TOS, PP and data collection.

It’s like sending an email to someone’s gmail address! Its content will be scanned, but yon don’t have to deal with Gmail running on your computer. With this, you can have a nicer client (especially desktop) that don’t have whatever unnecessary features WhatsApp wants to promote (like status and channels). Discord, Slack, Teams and Spotify are other services that are begging for alternative frontend.

In fairness to Facebook this is a very well written and fair post.

This is how the DMA should be done.

https://element.io/blog/the-eu-digital-markets-act-is-here/ gives some answers on the Matrix side