Racket got ported to be based off of Chez Scheme some years ago. [1] It's had to use a custom fork of Chez which (among other things) included support for Apple Silicon. That custom fork got merged back into the main Chez repo yesterday. I couldn't find an official announcement; the commit seemed to be the best there was.

Anyway, yay for the Racket and Chez teams!

[1]: https://users.cs.utah.edu/~mflatt/tmp/rkt-on-chez.pdf