No, all depends on the Apache configuration - what Apache (or any other webserver) servers for a particular request.
For example if you have PHP running the PurePath will follow to PHP. If you have some custom module serving your requests the PurePath will stop as it probably won't be a supported technology.
If you have Apache in reverse proxy configuration, the PurePaths will follow to the backend service.
Can you post a screenshot of service flow? A screenshot of purepath? And how is the apache HTTP Server configured? Just forwarding requests to Tomcats? How do you expect the serviceflow / purepath to look like?
Based on your description it seems the Service flow is IIS -> Apache HTTP Server -> Apache Tomcat.
Based on the information above I don't see any issues.
Maybe the PurePaths you are looking to really are served at the Apache HTTP Server (caching?)