Incoming Call opens URL
If there is an incoming call, Teams should open (if actived in the preferences) an URL with the number of the dailer. Many countries have public phone book services which can be queried "www.phonebook.com/0587777777" which can show the company who called me. It can also be used to start the customer data from the on-premise CRM system, if the URL lookup is possible. It should't use a lot of effort to add this feature in Teams Windows client to activate it and definde the URL.
Mike Ullrich commented
also very much needed for Dynamics 365 integration without partner tools or extra contact center solutions