I don't know much about how this kind of thing would be implemented, so I don't know whether it's feasible or not. But I just wanted to put my voice out there as agreeing to this. I think it would be a good idea, if at all possible.

You say there might be people who complain because they want to do symbol table manipulation, or similar things. Well, they can just turn off that warning. :-) People who are used to doing fancy things are already accustomed to turning off warnings and stricture when they need to. I can't see how this would be a major problem for them.