Is the list of needed IOTA updated by the system?

Today I checked my list of needed IOTA’s and to my surprise the list was getting shorter. Recently confirmed IOTA’s had been deleted from the needed list.
Is this an automated proces? Was not aware of that functionality.

73, Aart PA3C

The list of a user’s needed IOTA group references is not updated automatically. It should only change when you manually edit it or upload a new CSV file.

73, Manuel HB9DQM