Continuing the new upgrade streak:

dnf system-upgrade download --releasever=33

Easy peasy. The only wrinkle was related to openssh’s deprecation of ssh-rsa (https://lwn.net/Articles/821544), causing some issues with some connections. A quick fix ~/.ssh/config like the following is a workaround:

Host bitbucket.org
     User git
     PubkeyAcceptedKeyTypes ssh-rsa