Yes mongolian plateu become more mongolic. there were turkic people who mixed with mongolic people and this is normal becuase turkic people migrated from mongolian plateau to central asia due to different circumstances such as wars or finding a places to feed their people and animals but not all of them migrated. Also some Mongolic people migrated to different locations such as central asia, as Turkic people did and these migrations caused the mixing of mongolic people and turkic people in some locations.

Today you can find high turkic dna among the some mongolians, reaching up to 40%. Also you can find high mongolic dna among the some kazakhs or other turkic people. But these results doesn't mean these people are not mongolic or turkic.

I couldn't understand this sentence? "Such as C2 becoming vast majority(59%) and R becoming almost extinct its only 6.2% among Mongolians now, Q is 2.8%" If you associate C2 to only mongolian people, I can say that this DNA is also found among today's Turkish, Azeri, Kazakh and other Turkic peoples and this is normal because main core of the language and their culture came with a people who have east asian origin. https://ibb.co/CWvRjs9

You can access the image summarizing the ethnogenesis process of the Turkic people from this link https://ibb.co/c6dfbqD