When you assign a preset color to the Social Links block, it records the preset's hex color in the markup like so:

<!-- wp:social-links {"iconColor":"foreground","iconColorValue":"#000000"} -->

If someone were to go and modify the value of that foreground preset via Global Styles, the social links block does not update to the new color value. The original hex color defined in the block markup is still used.

GIF:

Note that I'm changing the color of "foreground" via Global Styles, but that update is not reflected in the Social Links block color:

Gutenberg version 11.7.0-rc.1
Noticed during the development of Twenty Twenty-Two: WordPress/twentytwentytwo#74 (comment)