Yeah I think he tried to get him to play right handed, but Henrix was a left handed player and used to play a right handed guitar upside down. There's a famous story about Eric Clapton buying Henrdix a left handed Strat, but he never got to play it as he died before Clapton could give it to him.
Being left handed was a nightmare as a kid, because it was always seen as a big no, no, and kids were forced to use their right hand. It actually helped me remember my left from my right in Italian funny enough for exactly that reason ie sinistra....which in Latin means sinister. Sorry, just one of the daft things i remember but using your left hand was seen as sinister....or a later detriment term of cack-handed. Hence I was forced to write with my right as a lad, exactly the same as Hendrix was forced to play with his right.