Google posted an update that it is currently working on linking your Google AdSense account with your Google Analytics 4 property as it offers with Universal Analytics 3.
The update was posted in this AdSense help document at the top and reads, "Google Analytics 4 update: We're currently working on an update to allow you to link your AdSense account with Google Analytics 4. We'll let you know when it's ready. In the meantime, we encourage you to continue making the switch to GA4."
This was spotted by Charles Farina on Friday who posted this screenshot of it on Twitter:
Well, we got less than 30 days Google...
Forum discussion at Twitter.