UPDATE: Jan 29, 2018 – statement of Microsoft: “Based on overwhelming demand from customers on the continued need for Dynamics 365 for Outlook for their business scenarios, we have decided to not deprecate it…”
Is it or is it not? Perhaps this question has not yet been finally answered… The last offical statement is:
“At the end of June, we announced that Dynamics 365 for Outlook (“Outlook add-in”) is deprecated with the July 2017 update for Dynamics 365. The Outlook add-in is a legacy feature that has been around for a while. In this blog post, I’ll provide more details regarding this announcement.
When a Dynamics 365 feature is “deprecated,” it means we intend to remove the feature capability from a future major release of Dynamics 365. The Outlook add-in will continue to work and is fully supported until it is officially removed. However, we will not invest in new functionality for the add-in. After removal, the Outlook add-in will no longer work.”
You find the original article in MSDN blog here: https://blogs.msdn.microsoft.com/crm/2017/08/08/deprecation-of-dynamics-365-for-outlook/
Or in this blog with a list of drpeciated functionalities in Dynamics 365: https://community.dynamics.com/crm/b/crmtipsfromadeveloper/archive/2017/07/07/dynamics-365-crm-july-2017-update-list-of-depreciated-functionalities-in-d365