Some important changes were made in the installation process this time around with the CC apps. By default, UNLESS YOU TURN THE FEATURE OFF, installing InDesign CC 2015 will UNINSTALL PREVIOUS INDESIGN CC VERSIONS. You must click on the arrow next to Advanced Options (to view those options), then UNCHECK "Remove Old Versions" if you want to keep them installed.
Read all about it at this InDesignSecrets.com blog post:
Thanks Steve. As we have not yet transitioned to the new Adobe DPS, we still need Folio Builder and what not... things the 2015 version of InDesign are missing.