All pre-flight means is that you ensure that all the necessary pix are included as cmyk tiffs and that all used fonts are included. That was way back when. Now stuff for print goes off as PDFs, you need to check that page size is correct, corner marks are included on each page and that the fonts show up correctly - best done on a machine which is stripped of extraneous fonts. Of course, you need to know which fonts are intended. A passage of text might look very professional using Time New Roman but that's no good if the customer's in-house font is Palatino.
Use your own good common sense and keep your wits about you and you won't have to deal with an angry customer recall on 200000 catalogues!