To anyone reading this post; THIS IS THE FIX
1. Ensure you've factory reset the Chromecast device
2. In the Aruba GUI, go to More-->Services
3. Under the Airgroup tab, check the Enable DLNA box
4. Under AirGroup Service, enable the following:
-googlecast
-DIAL
-DLNA Media
Everything else in this section remains unchecked/disabled
5. Go through the initial Chromecast setup process.
Done. My Chromecast is now able to join my corporate wirless network