Copssh version 6.2.0 installers contain OpenSSH 7.7p which is primarily a bugfix release. Major relevant changes:

• ssh(1)/sshd(8): Drop compatibility support for some very old SSH implementations, including ssh.com <=2.* and OpenSSH <= 3.*. These versions were all released in or before 2001 and predate the final SSH RFCs. The support in question isn't necessary for RFC-compliant SSH implementations.
• sshd(8): Add "expiry-time" option for authorized_keys files to allow for expiring keys.
• ssh(1)/scp(1)/sftp(1): Add URI support to ssh, sftp and scp, e.g. ssh://user@host or sftp://user@host/path.  Additional connection parameters described in draft-ietf-secsh-scp-sftp-ssh-uri-04 are not implemented since the ssh fingerprint format in the draft uses the deprecated MD5 hash with no way to specify the any other algorithm.