That was exactly what I needed! I had been looking at the Fortinet Support site in the Downloads area. The SSL VPN free version of the FortiClient isn't available in the FortiClient 6.2 area there, so that's what led me astray.
I've been able to get the correct installer from www.forticlient.com as per this section of the release notes you mentioned above:
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.