Please submit your request to Tableau Support and provide them with more information.
I don't like what I'm seeing in your logs. Your postgres db is not accepting your connection so either the username and password are incorrect (the username hasn't changed so it has to be the password). In server 8.2 the postgres superuser password is blank and in 9.0 is the password is created at the time of installation. Then I move up a bit and this is the part that I don't like.
Why is Tableau enabling inbound firewall rules for Tableau Server 8.1 and 8.2? Did you not uninstall 8.1 or 8.2 before upgrading? Like Toby said please submit a case to Tableau Support.