issues i see
1. proving the decendants
2. proving the original slave was not compensated when they were freed
after all having kids while  slave was not a massive thing to happen. so the decendants would usually have been birthed after the slave was set free.

yes there were many cases where decendants were the result of master/slave rape and yes that should be compensated. but trying to gather evidence from over 100 years ago of what actually happened and if the slave was previously compensated fairly. makes this new policy hard to determine