Reviews that aren't updated for two or more years will disappear from your member profile page and from below your forum posts on the grounds that they're probably too stale to be interesting or still accurate. These reviews can still be found on the site in the appropriate vendor pages, as all reviews are kept for historical purposes.
As mentioned in this section ( »Site FAQ
»How do I edit my ISP review?
), a significant update is required before the review shows as updated - somewhere near ten percent of the text needs to be changed, added or removed.