Any of the suggestions in this thread would be an improvement but if the two parameter suggestion is semantically clearer then it deserves further consideration
when you very first start and are introducing the idea of digital input and don't want to introduce to many things at once.
Digital input is almost always introduced using buttons. These require pull-ups so the concept does need to be explained from the start, although often an external pull-up resistor is introduced before internal pull-ups. However I think that many non-technical people would find it easier to get something going if the button example used internal pull-ups instead of the external pull-downs:
pinMode(buttonPin, INPUT_PULLUP );
rather than having to understand and deal with : “a 10k resistor needs to be attached from pin 2 to ground” (sounds of user fumbling through pack of components trying to find the correct resistor)
Breaking existing code would be a problem but I wonder if there is any code that relied on the pull-ups being enabled when changing from output mode to input mode. Pull-ups change their state if the pin is switched to output mode and the pin state is changed, so code that does not explicitly set pull-up state when switching from output to input is a potential source of bugs. Is anyone aware of any code that does switch from output to input that requires pull-ups in a particular state but does not set them explicitly. If not, assuming the current method for setting pull-ups was still supported, old code would not break.