There isn't any "chemically extracted" seed oil, at least not with a chemical reaction. The use of a chemical reaction is indicated by "interesterified" or "hydrogenated". That isn't used for extraction; it alters the melting points.

The use of solvents to extract oils isn't a chemical reaction. It's not really different from using CO2 to extract caffeine from coffee, using water to extract tea from tea leaves, or using alcohol to extract vanilla flavor from vanilla beans. The common solvent for oil extraction is hexane, which is removed by boiling it off with a vacuum and/or heat.

The solvent-extracted oil will have unmodified molecules. The proportions of the various molecules may differ because the ease with which they are extracted will depend on the processing conditions. You get different proportions of molecules in the mix if you change the temperature, pressure, time, or solvent. For some use cases you might prefer one mix or another. You could get a different viscosity, melting point, or smoke point.