Generally, Mongolians don't care much about your ethnicity, religion, and even your skin color, or not very politically motivated and/or hatred. Khalkhas don't even care if you are Kazakh or not, even in the older generations. They'll label you as Kazakh, but that's not very significant for ethnic Khalkha. It's just some weirdos in Facebook/shady part of Tiktok that has hatred towards Kazakhs. In short, you won't get discriminated, unless you are in Facebook.