I never heard this before. Do you have a link to a research to confirm this? Are you talking about laying hybrids?The only chickens that rarely have crop issues are free range chickens.They can afford to be picky
I never had crop issues with my flock (6-9 bantam chickens for 10 years). They free range sometimes but are confined to a net covered run most of the time. I just don’t feed them long grass in the run and they have always access to grit in the run and small stones in my yard.