My wife’s family farms/ranches in western Oklahoma and central Kansas. 30+ years ago they sprayed weeds after harvesting the wheat, then either plowed, disced, or harrowed the section depending on the weed infestation. Wheat back then had not been genetically modified to resist glyphosate, so it could not be applied once the seed had sprouted.
Farming is considerably different today. I challenged the OP on the claim that glyphosate was used often on wheat right before harvest. In this area of the country it is not. I do wonder what the science will say 30 years from now about our farming methods today. Time will tell.