|Cadet Corps at Eton Drilling|
No, says the BBC in this 2014 article.
Although the great majority of casualties in WWI were from the working class, the social and political elite were hit disproportionately hard by the war. Their sons provided the junior officers whose job it was to lead the way over the top and expose themselves to the greatest danger as an example to their men.
Some 12 percent of the British Army's ordinary soldiers were killed during the war, compared with 17 percent of its officers. Eton alone lost more than 1,000 former pupils—20 percent of those who served. UK wartime prime minister Herbert Asquith lost his son Raymond, while future prime minister Andrew Bonar Law lost two. Anthony Eden lost two brothers, another brother of his was terribly wounded, and an uncle was captured.
|Grave of Lt. Raymond Asquith at the Somme|