User blog comment:Rappy 4187/Technical Update: May 4, 2015/@comment-4714517-20150506064529/@comment-126761-20150507184617

The display of 'best practices' note in the preview dialog is indeed still under review - we just have limited development resources, which means that we can't do everything very quickly. While we would certainly like to avoid taking a long time to make certain changes, sometimes it can be unavoidable due to resource constraints. It's true that, since the Wikia feature-set has grown a lot in the past few years, it has meant some things have got a little left behind - we're going to make more efforts in the future to avoid this.

It's worth reiterating that these notes are not comprehensive - we try and pick out changes that users will notice, or want to hear about. Features that may appear untouched may be receiving a variety of backend improvements and bug fixes. In fact, some entire backend systems have been replaced more recently  - but it's been done smoothly enough that no-one (outside Wikia) has noticed.