It's possible that the VDB was filled in with grease/debris. I think the coin you are thinking of that people are always talking about is the 1969-D no FG. https://www.cointalk.com/threads/5-1969d-no-fg-from-my-penny-jar-any-good.229959/
I have seen some coins being marketed as "Missing VDB." The ones I have had the pleasure of looking at under the microscope were late die state coins. In other words the VDB was missing because the die was heavily worn. Here is an example of what I'm referring to.