No, Raggy; that was a foul canard. Here's a quote from Wikipedia:

"After retiring from the service, Haig devoted the rest of his life to the welfare of ex-servicemen, making many speeches (which did not come easily to him) and answering all letters in his own hand.[232] Haig pushed for the amalgamation of organisations, quashing a suggestion of a separate organisation for officers, into The Royal British Legion which was founded in June 1921. He visited South Africa in 1921, Newfoundland in 1924, and Canada in 1925 (visits to Australia and New Zealand were being planned when he died) to promote ex-servicemen's interests. He was instrumental in setting up the Haig Fund for the financial assistance of ex-servicemen and the Haig Homes charity to ensure they were properly housed; both continue to provide help many years after they were created."

The source of the above information is "Douglas Haig, 1861-1928" by Gerard J. de Groot, published in 1989.

Whatever his failings as a commander in the field, it is clear from plenty of evidence that his post-war life was dedicated to helping veterans.