does anybody know when Rocky 10 will be officially supported for downstream clusters?

I've been using Rocky 9 (also Debian 11/12) but to be honest we ended up switching to OpenSuse-leap-micro as its from the same stable, and because its light and small it provisions in half the time and we've had far fewer issues with quirky things with cloud-init. Also NFS support works out the box with the micro image. If your ultimately running containers in the desired flavour you really want the nodes hosting your workloads need not be specific.