When you duplicate the page with inlined (pinned) objects on a text path, you get a mess.
The procedure is as follows:
1. Create a path.
2. Make it a text path.
3. Create any shape on the page with any shape tool.
4. Copy this shape to clipboard.
5. Paste this shape on a text path multiple times as an inlined (pinned) objects.
6. Duplicate this page.
7. Get a mess.