Perhaps. The problem is, if you use PFCT on a bunch of hosts and something subtle changes that can cause issue, the granularity of the PFCT doesn't necessarily equate to that required for detecting the cause. With a CSIE-style atomic approach to deployment and a properly segregated monitoring system, you can, say, 'roll back' to the last known good version. PFCTs leak state, and will not always allow you this reverse pathway (random examples might include kernel feature or compiler version migration).