Likely not, but I've been in or around Naval Aviation for 28 years, so I'll give it a shot anyway. Additionally, I speak with someone actually doing this depot level work on a near daily basis. I got the low down from him on this particular issue last week.
There are and have always been different levels of maintenance for corrosion control. There are areas that squadron level maintenance never gets to. They simply cannot be accessed without putting the aircraft out of commission for weeks. Even at the depot level, there are a few areas that are not normally accessed. The issue is in one of those areas.
I presume that the engineers decided that within the projected 6000 hr lifespan of the aircraft, this area would not become a problem. They were in fact correct.