Apple released version 11.2 of iTunes this past weekend. 11.2 contains a behavior change that prevents Titanium applications from installing to device via iTunes using the Titanium CLI, Titanium Studio, and Appcelerator Studio.
This only affects development and test device builds when using iTunes. Simulator testing and publishing to the App Store is unaffected.
We are tracking this issue in ticket TIMOB-16987 and should have a fix available in the CI loop very soon. In the meantime, there are several workarounds: