I have heard it said, and said it myself. Here are the scenarios:
1. Where I work know, we have an airport with an ILS approach in an area with very poor radar coverage. In fact, we lose radar contact on most aircraft flying the ILS. After saying radar contact lost, I will ask them to report established so I can switch them CTAF. It is a non towered airport.
2. Where I worked long ago we had an airport with an ILS approach, but the localizer was not drawn on the video map. In order to vector aircraft for the approach, we would give them vectors and ask them to report established. After they reported established, we could clear them for the approach. The alternative was to fly the entire published approach with a procedure turn.