We need a new form of X-ray protection.

[Naamandre3]

Yes, they can. Because they still see large hole in the ground, whether it's filled with ore or not.

Actually, if i understand the way this protection works.
It does not show a large hole in the ground. it would show a layer under the dirt filled with the random ores (Like shown in the screenshot) and you would not be able to see a large hole.
So yes its more effective then the older protection against things like this.

But i can see the annoyance of players. I suppose in the end it all comes down to what player wants. a better safer way to keep you're underground bases but have 'fools gold' as pavja told. or have a less effective method maybe allowing x-rayers to find big holes underground but no 'fools gold'