This is nice, although it was possible to run a 64bit kernel before [1].

[1] https://www.sindastra.de/p/1345/switch-your-raspberry-pi-to-...

Raspberry Pi OS has had a beta release available for over a year now, and it's tracked upstream Debian closely. It's been great to work with, and now that it's out of beta, I can recommend it more broadly than before!

The OS part I think implies a userspace compiled for 64 bit.

Finally out of beta! Good to see.