I have heard about the bitlocker issue with Cyan release. My work site uses activesync policies and forced bitlocker on my phone. If I remove the email account for exchange will bitlocker be turned off and thus I would be able to do the Cyan upgrade?
It only affects those on 8.1 Preview. If you're running 8.0 and part of a corporate network (which by the sounds of it you are), then you can go ahead and update with no worries.
You could try turning off the company apps and stuff and removing the Exchange account but I suspect if policies are being enforced then those options may not be available.
Only way round it is to use the recovery tool and downgrade to 8.0, reinstate Exchange and stuff, then do the update. Or do the update first lol.