On the Sci-Fi/Fantasy site, a user asked what "What's the meaning of '411 on the late-night drop box'?," a line from Captain Marvel, which was set in 1995.
Another user answered that it meant "how to use the video return slot" (correctly, IMO), but made an off-hand comment that "the 411" was considered Black slang. They certainly seem to be correct that it originated from Black culture, namely Aretha Franklin's 1982 song Jump to It.
However, many commenters remarked they didn't think it was specifically associated with Black American English, a sentiment I would have shared. Even Urban Dictionary, a site which ... doesn't really shy away from slapping racial labels on things doesn't mention anything about being associated with Black Americans.
Neither does our question/answer on it, in fact the top/accepted answer links it to Valley Girl subcultures, which, while very '90s, is definitely not Black.
So, the question is, would "the 411" have been marked as Black slang in the '90s? Or even in '82?