After cancelling my hosting, I noticed my e-mail reports stopped working. Since I also upgraded my server with a troublesome version, I originally didn't connect those two. However, issue with reports persisted even after I fixed the e-mail issue.
Manually running report immediately identified the problem. You see, I login to every server using public key. As my login on DreamHost server was gone, SSH simply decided to fallback to keyboard authentication. And so report waited for keyboard input that was never to come.
Solution intended for this troublesome issue actually already exists in the form of BatchMode option. Appending -o BatchMode=yes to SSH command will cause it to rather fail than ask user for anything. Exactly what doctor prescribed for my report script.
With this update, my "standard" SSH crypto settings for the report got updated to:
ssh -2 -o KexAlgorithms=diffie-hellman-group-exchange-sha256 -c aes192-ctr -o MACs=hmac-sha2-256 -o BatchMode=yes example.com