How To: Disable the automatic basemap in new maps for ArcGIS Pro
By default, creating a new map in a new project in ArcGIS Pro automatically adds a basemap service to the map. This is the default basemap service defined by the organization, but usually the default is the Topographic basemap.
It is possible to disable the automatic topographic basemap service for a new map. The instructions provided describe how to disable the basemap service for a new map in ArcGIS Pro.
Select the PROJECT tab to open the file menu.
On the left-hand menu panel, select Options.
In the Options dialog box, select 'Map and Scene'.
Under the section for setting the default options for new maps and scenes for basemaps, click the None button.
This disables any basemap service from being added automatically to new maps. The type of basemap added can also be changed by selecting 'Custom basemap' in the Options dialog and selecting the desired basemap from the drop-down menu.