The checksums are automatically included with the models when you download them using the download.sh script, and verified right after the download completes. This isn't unlike how a lot of packages distribute the SHA256SUMS file next to their downloads over HTTPS, which you can validate yourself.
That said it would be nice to announce them somewhere else but if you're already downloading them from Meta directly the need for third party verification is much smaller IMO. Torrents will come soon enough anyway.