2 had titles. 2 were straight commoners. The others had aristocratic roots.
-Lord Nicholas: DOK son
-Edward VC: Charles' godson. Yes rich, and lived in Amner, but commoner
-Lady Sarah Chatto: Margarret's daughter
-India Hicks: daughter of Lady Pamela Mountbatten
-Catherine Cameron- female line granddaughter of Marquis of Lothian
-Clementine Hambro-female line great-granddaughter of Churchill
-Sarah-Jane Gaselee-commoner, father was racing friend of Charles
Sarah was the one with the heavy named bridal party but again not all.
-Zara- no title but RF
-Laura Fellows- Diana's niece, noble blood on both sides
-Rosanna- daughter of the Duke of Roxburghe
-Alice- Sarah's half-sister
-her nephew Seamus
-her half brother Andrew
Anne had 1 each, Lady Sarah and Prince Edward.
I think the poster meant that it was the first time that None of the kids came from an aristocratic family. Not that first time All of them didn't.
Generation back would have been even rarer. The queen had 2 princesses (hr sister and Alexandra), 3 ladies (Lady Mary Cambridge, Lady Elizabeth Lambart and Lady Caroline MDS), 3 honorables (Honorable Pamela Mountbatten, Margarat Elphinstone and Diana Bowes-Lyon) and 2 Princes (William of Gloucester and Michael of Kent).
Margarat: (not sure she had pages, Philip gave her away)
-Marilyn Wills-granddaughter of Margarat's Aunt Lady Elphinstone
-Annabel Rhodes- another granddaughter of Lady Elphinstone
-Virginia Fitzroy- daughter of the Earl of Euston
-Sarah Lowthar- daughter of Sir John Lothar
-Catherine Vessi- daughter of Viscount de Vesci
-Lady Rose- daughter of the Duke of Abergavenney