https://bugs.winehq.org/show_bug.cgi?id=46447
--- Comment #3 from Rosanne DiMesio dimesio@earthlink.net --- Sounds like you are looking in http://dl.winehq.org/wine-builds/debian/pool/main/, which is where the old packages were stored.
Packages are now stored in http://dl.winehq.org/wine-builds/debian/dists/buster/main/binary-i386/ and http://dl.winehq.org/wine-builds/debian/dists/buster/main/binary-amd64/.
You probably haven't added the new repository key, either. You need to, then run sudo apt update and answer yes when it prompts you to accept the repository changes. https://wiki.winehq.org/Debian