Absolutely. You can make general guidelines for diets. However, when you go into specifics like carbohydrate/fat/protein fractions it is very much dependent on the individual. Include then the difference in gut microbiome between people and it becomes even more complicated.
While this talk is very interesting, I'm a little critical of their use of the glucose response as the end all be all parameter indicative of a healthy diet. I would have to look into their research to see their underpinning of why they think glucose response can be used in this matter.