Mama Thorton barely a fucking penny off of Elvis' Hound Dog's success. Jerry Leiber and Mike Stoller got the writer's credit on that one, and thus the writers share of the original royalties, but they didn't have a publishing share, and thus saw very little actual money. The only profit they would see is if consumers would find out they originally did the songs and buy their records too. So no, black performers were not getting money from his success. The only black musicians that profited from Elvis' success were those lucky enough to get a spot on Tom Parker's tours with him. Who was, by the way, notoriously racist, so that was a hell of a selection process.

This isn't some tumblr-fueled "your fave is problematic" embellishment and digging, this is the truth of how the music industry was at the time. Elvis was far from the only one to do this, but he was absolutely the guy who got the most famous off of other people's songs