My thoughts on 23 years of Bus flying: Yes, it happens where you make an FMA call based on what you expect as apposed to what you actually did. Calling open descent when you didnt actually pull the knob far enough for example may give evidence that calling the FMA serves no purpose.
But more often than not the reverse happens where the FMA call is exactly what picks up the oversight. Forgetting to arm the approach then going to read the FMA and finding it aint correct saves me more than the first scenario.
Its not going to catch your errors every time but it does help.
I have just joined my 7th airline where FMA calls are SOP however often not done and the number of errors is significantly higher than previous carriers.
Another call my new carrier does differently is the rad alt alive. Previous SOP for years was 2500 "rad alt alive" but my new carrier is 2500 "checked". Throw in that checked with several other "checked" calls down the approach and its easy to overlook the fact that the ground is coming into play. In this day and age of CFIT awareness I am surprised that there is such little attention paid to the rad alt????