It seems that the calls are survivable. I just tried this on a CCM -> IPCC system (still under test, not production).
Called into a route point, it seized a CTI port, the call is still terminated at the IVR. I reset the port and nothing happened.
HTH
PS: please remember to rate posts!
Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus