Actually, by default we show the citations as blue underlined citations in the form (Do et al. 2012). These are easy to spot in the document.
Once you format the citations they get their final form. We can't change that because that's how it's printed and how it's exported. The output would be wrong.
However, you can revert to the blue placeholders by using the sidebar add-on and clicking "Unformat". We've added this function for exact this use case.