I've just completed my dissertation on suburban development and the development of new towns. I read quite a lot of material on the development of London suburbs, and didn't find this mentioned - that doesn't mean it didn't happen though.
I did come across a quote from William Burt, the General Manager of the North Eastern Railway - who told the Royal Commission on the Housing of the Working Classes in 1885, that the "workmen's escape routes to the suburbs should be strictly limited" to avoid spoiling suburbia. Quite a surprising attitude, but certainly the development of working class suburbs were not initially driven by the railways. Those for the middle classes were a different story.