Or have any aunts or uncles.
They really have depleted the nurturing, natural bonding experiences their DCs could have had with extended family - share holidays, parties, birthdays etc.
For Meghan she wouldnt know any better as she did not have this grounding and enriching experience in her own childhood - but Harry was close to his many cousins and will soon reflect and feel the loss these decisions will have on his own DCs childhoods - I expect as babies/toddlers the penny wouldn't have dropped - but as they become 5+ he will remember his own experiences.
All they can offer their DCs are transient, transactional, shallow connections with their ever decreasing LA unstable 'social' circle.