I find it extremely implausible that either the York or Edinburgh offspring will be called upon as working royals at any time in the foreseeable future. Looking at the other European kingdoms, even all adult
siblings of the monarch or heir to the throne either have been fully excluded or retired from royal duties (Margarita, Elena and Cristina of Spain, Irene of the Netherlands, Marie-Christine and Esmeralda of Belgium, Margaretha, Birgitta, Désirée and Christina of Sweden, Anne-Marie of Denmark, Märtha Louise of Norway) or, if they remain official working royals, have been reduced to a more or less minor role (Margriet and Constantijn of the Netherlands, Astrid and Laurent of Belgium, Carl Philip and Madeleine of Sweden, Benedikte and Joachim of Denmark, Astrid of Norway). None continue to involve cousins in official duties beyond the occasional family event. Nothing about the British monarchy or British culture insulates them from the same influences that have already caused the reductions in working royal families in the other major European monarchies.
The point still stands that the message for a "slimmed-down monarchy" was geared to say that any grandchildren of the monarch will not become working royals, regardless of their titles.
The Wessex children were never expected to be working royals - hence no royal titles from the get-go.
Iluvbertie is correct. The official message in 1999 was that the children of Prince Edward would not receive royal titles
because they were not expected to be working royals.
In a modernising touch, the couple's children will not be given the style His or Her Royal Highness, "but would have courtesy titles as sons or daughters of an earl".
The decision reflects "the clear personal wish of Prince Edward and Miss Rhys-Jones as being appropriate to the likely future circumstances of their children," said a spokeswoman before Saturday's wedding.
BBC NEWS | Special Report | 1999 | 06/99 | royal wedding | Wessex titles for Edward and Sophie
(Of course the fact that the Sussex children, who are in the same position, received royal titles in spite of not being expected to become working royals throws doubt on that explanation, but that was what was announced in 1999.)