I agree with Martjin and Ecmaster76. Setting up a Deployment Site is not practicable for many customers and a "pre-production" switch would be ideal.
Anyway, unfortunately, the script from Jeff does also not cover the issue, that immediately after installing the first Exchange 2016 server, his default FQDN set on all the virtual directories, used by the client will be published.
>>See topic "list" under the section "namespaces and Active Directory Site Topologies" in the article by Ross IV.:
http://blogs.technet.com/b/exchange/archive/2015/10/06/namespace-planning-in-exchange-2016.aspx
http://blogs.technet.com/b/exchange/archive/2015/10/06/namespace-planning-in-exchange-2016.aspx
This situation will bring up instantly the issue that Outlook clients receives a Exchange Proxy URL with the mentioned FQDN of the new Exchange 2016 server until you change it and before you'll get time to finalyze other configuration "Exchange admin" tasks.
Today we had the problem described by Martjin here again with a customer:
https://social.technet.microsoft.com/Forums/en-US/d37afaed-da76-4201-9d3d-5eee834b6ebc/outlook-20102013-profile-issues-after-installing-exchange-2016?forum=Exch2016SD
It would be good if the product group checks again other variants...