That seems a bit extreme. He may be right, but I've found with movies and TV shows, the meta data isn't updated in the iTunes database after I've made metatag edits to the files in the iTunes folder unless I then go back into iTunes, select the show of interest and Get Info on it (Command-I within iTunes). At that point, what is displayed in iTunes then updates visually. Maybe it works the same way with the Music folder items. Delete and reimport? I doubt it. But I haven't tested this idea with music.
Note: I don't actually do ANYTHING within the iTunes Get Info window -- only view the file, select the next one, and next one
and click on Cancel in the end. All data, including the parts that are not editable within iTunes such as MPAA rating, populates from what I added with my tag editor of choice (Subler).