More detailed studies would be required to actually confirm the link between C-sections and evolution, as all we have now is a hypothesis based on the birth data.
Agreed, more studies required part. Cesareans may simply be becoming more common with “too large” defined as cesarean seems like a better idea. It's reasonable to pose the question based simply on an understanding of evolution. Like it's reasonable to conjecture that length of human pregnancy is a compromise between further development in utero, and chance of mother and baby surviving the delivery.