At ArcGIS Pro 2.0, ArcMap patches other than rectangle, zig-zag and other default patch styles are not supported. I attempted to import a *.mxd with other patch styles and they did not import with the *.mxd. I'm hopeful the next release of ArcGIS Pro supports non-default patch styles.
I couldn't agree more. The lack of this feature restricts good cartography. When it is important, at least I can import the patches as graphics. Thanks for the reply. Nice to know someone else is having the same issue.