I don't think it's out of line at all to have some prefacing remarks in the beginning of a thread such as this which is focused on racially charged issues. Nor do I think it's out of line for someone to point that out when the opening statement doesn't provide much of an overview.

I just did a similar type of comment on a thread focused on Indian sea songs and shanties, along with a substantive contribution to the topic.

My own family had direct testimony from a returning Black WW 2 veteran about the racism that was rampant in our training camps; he was imprisoned for organizing a protest.

Charley Noble