The point is there never was proof in the first place that they are needed. It doesnāt exist, and I posit that it canāt be shown, because itās not true.
As to micronutrients, meat is far more nutrient dense than plants, the nutrients are more bioavailable, in some cases by an astounding degree, and unlike plants, meat doesnāt come with anti-nutrients.
I do have posts on the topic, for example:
Are vegetables good for you?
Meat is best for growing brains (This one is āaboutā something else, but has a lot of relevant information.)
I would also recommend the website of Dr. Georgia Ede, for example this post:
http://www.diagnosisdiet.com/food/vegetables/
It is fact that of the post-modern peoples who survived after our best food source, the mega-fauna, went extinct, several societies thrived on only meat, including Inuit, Maasai, Mongolians, and various tribes of Plains Indians. Vegetables are not necessary for health.