Parents who spent years limiting purchases to home necessities and kids' entertainment often embrace more luxury-oriented buying patterns later in life. this phenomenon is related to

- Empty Nester Behavior.

Explanation:

'Empty Nester Behavior' is demonstrated as the genuine sense of sorrow or loss that leads to a feeling of isolation and despair(depression) in parents when their kids get matured and begin to live independently.

In the given situation, the phenomenon is associated to 'empty nester behavior' as the parents 'purposes are being shifted' and they experience a  very real kind of loneliness or grief when 'their kids are embracing their own preferences('buying luxury-oriented patterns which is different to the parents' 'limiting purchases'). This independence of the kids leads to develop a sense of loss among the parents.