There is no field dedicated to announcing corporate actions and name changes in advance.
After a name change, the DSPLY_NAME field of the old RIC will hold a comment referring to the new RIC: **SEE<NEW RICNAME>. This comment will be removed after a few days.
In Eikon you can search for effective name changes (there is no advance information) starting from page WORLD/CHANGE1. For a specific country, use <countryISO>/CHANGE1, like DE/CHANGE1 for Germany.
Example from DE/CHANGE2 (see screenshot 1):
Example from DE/CHANGE6:
Corporate actions are provided by other products and APIs, such as DSS (DataScope Select).
To find out about name changes in advance, Thomson Reuters customers can subscribe to Data Notifications emails through the Thomson Reuters Customer Zone. These emails document in detail all kinds of upcoming data changes.