Many ArcMap styles have been retired and are not included as system styles in ArcGIS Pro. However, you can import ArcGIS Desktop styles into ArcGIS Pro.

Does ArcMap come with ArcGIS Pro?

Although ArcGIS Pro uses a new ribbon interface, it uses the same familiar basic concepts—maps, layers, and basemaps. ArcGIS Pro is included with the ArcGIS Desktop product. If you have ArcGIS Desktop and are current on maintenance, you have access to ArcGIS Pro and can download it from My Esri.

Is ArcGIS Pro replacing ArcMap?

Esri announced at the 2017 International User Conference that ArcMap will be replaced by ArcGIS Pro. Although many of us have been predicting this action, Esri has finally confirmed that Pro will be replacing ArcMap.