This is not known or proven. At one time they were called American Sebright Cochins, but there is no proof Sebrights were used in the breeding. Hamburgs, Brahmas, and Cochins are documented as sources of particular genes, patterns, and colors. There was at one time a deliberate breeding effort to produce hen feathered Silver Laced Wyandottes which were considered more "showy" than the normal feathered variants. Hen feathered carries several genetic problems due to reduced testosterone levels in males. When combined with the rose comb inversion that whacks the sperm motility gene, the result is a bird that has difficulty reproducing. Sebrights show these difficulties. The advantage of hen feathered includes fully laced tail and hackle feathers. The disadvantage - particularly when combined with rose comb - is difficulty maintaining and reproducing them.
There were conflicting objectives in early breeding efforts. Eventually they were stabilized with very pouffy tails and very soft fluffy under and rear abdominal feathers. Rose comb was chosen as breed standard because it contributes to winter laying capability. Large birds, very cold tolerant, lay all winter, can go broody are today's Wyandottes.
Also, ColtH, Well bred SLW do have lacing up the tail. They are not fully laced like Sebrights.