Have .notdef boxes gone out of style? I used to leave them blank because I didn't realize how critical they were for typographers in preventing expensive disasters. For example: going to press without spotting missing glyphs. Recently MyFonts (the new site) added a choice of multilingual pangrams. So give it a try. Switch your sample text to Japanese and browse. If my .notdefs are missing it's because I forgot to add them. But some font designers seem to always leave them out and most do it about half the time.
My point: does anyone deliberately leave .notdefs blank? If so, why?