They responded after this though saying that the binaries are coming. I don't know if they've been released yet.

I still don't see anything where Google replied later saying the binaries are coming. Do you have a link? This article was from 2 days ago.

Android Authority

The days of custom Android ROMs are numbered, and Google is to blame

CalyxOS, a privacy-oriented Android fork, has announced a pause on updates. But given the challenges most custom ROMs face, will it return?

"Google has now stopped providing driver binaries and device trees for Pixel devices as part of the AOSP’s code."

I went and found the tweet. Damn. I remembered it incorrectly. It seems the omission was intentional because they want to support a cheaper reference device, one that's not a $1000 Google device. That makes sense, but damn does it hurt custom ROMs. "AOSP needs a reference target that is flexible, configurable, and affordable — independent of any particular hardware, including those from Google.” That said, in the for decade of custom ROMs, most popular devices form Motorola, HTC, Samsung, etc were all getting the custom ROM treatment and none of these had device binaries or radios released.