I've always culled them, so I can't say for sure that they wouldn't mature without showing red. Day-old chick down can be drastically different in both color and pattern than mature feather color/pattern and with each molt juvenile birds get closer to their mature colors/pattern, but once they start feathering I believe the mature colors are showing up already even though the pattern may have a long way to go.
I don't double mate any of the varieties I breed and don't believe there is any correlation between salmon breasts of silver (wildtype) females and the red in males that you are referring to. Often the red in the shoulders of silver males is attributed to "autosomal red", but with some folks that can be a broad brush term about an unwanted red that we don't know enough about. It is easily bred into a flock and can be difficult to breed out, since the females may carry it without showing it. Test mating is something I haven't taken the time and space to do.
In the past I've bred both LF and bantam silver Ameraucana lines that didn't have the problem (Jerry Segler and tell you), but with recent outcrosses to make other improvements I've seen it pop up.