Not necessarily, and in this case most likely not. We are seeing the part failures early, and many repeat offenders. This indicates something else in the engine is causing the issue. While the phasers are the failure point, lack of oil flow to the phasers is the driving mechanism. Revisions of the phaser can make it more robust (ie operate with less oil, greater range of adjustment, etc), but if the problem exists elsewhere, it will fail again.
I've seen over 10 trucks with cam phaser replacements develop the problem again shortly after the fix. This indicates the problem is not with the component itself, but elsewhere. It makes complete sense to me that it would be a failing solenoid.
FWIW, I still calculated less than 1% of all Gen 2 Raptors have seen this problem. My dealer (which sells probably 20 Raptors a year) has only had a handful of regular F150s in for the fix, and no Raptors.
Exactly. Regardless of whether engineering determines that the issue is with the design or a manufacturing issue, a new service part number will still be released. This is the indicator to whether a suspect part or "clean" part has been obtained.