Well...the genetic stripe is a proven genetic, so I don't see how that one could have anything to do with the incubation process. But if they're saying that messing around with the temps will cause more striping in an otherwise normal bp....??? I have no idea...I suppose it's possible, but I've never heard of it.
But if I were incubating eggs, I'd be WAY more interested in being absolutely sure (as sure as anyone can be) of hatching out healthy animals, rather than goofing around with temps to try and manipulate non-genetic appearance.