Hi Ray,
I've submitted a bug to have this addressed (SDOCM00108276) for future TI-RTOS releases.
I noticed the TI-RTOS Kernel's (sysbios) User's Guide does mention the full module's name, such as "ti.sysbios.knl.Mailbox". You can use that as a guide to add the #include path in your application:
ti.sysbios.knl.Mailbox -> #include <ti/sysbios/knl/Mailbox.h>
ti.sysbios.misc.Queue -> #include <ti/sysbios/misc/Queue.h>