Um, would this be the part you are refering to?
That is not talking about breeding from hens with problems. When you breed from hens with no problems, you sometimes still get chicks with problems. Hatcheries normally cull the chicks with problems. This suggest that hatcheries may be sending out some of those chicks instead of culling them. It does not say anything about changing which hens are being used for breeding.
Given the time it takes for chickens to grow up and start laying, the ones producing eggs now would have been young chicks sometime last year. Most of the selection, and culling pullets with problems, would have happened before the hatcheries were taking orders for this year's chicks, so they would not yet have known how fast chicks would sell this spring. By the time they knew, they had probably already culled any pullets with detectable problems.