Yes, and the article even notes this information value to the user. That's why every published book still carries a notice. If someone needs to know, it can be

Yes, and the article even notes this information value to the user. That's why every published book still carries a notice. If someone needs to know, it can be looked up easily. But in a software project that's being continually updated, to know what's covered by copyright at any particular time, you'd have look at the change dates in the code base. Maybe displaying a 'last updated' date to the user might be useful. Usually the user wants to know: is this still maintained or is it dead? Is it current?