I don't agree with Orisa being F in Reinhardt's current state. Everything she does at a high level is just a better Rein. You'll see in OWL She's a better duelist, does more supporting damage, has a stronger shield, and can take more damage. She's strong against spam like Junkrat which is super helpful right now - more shield up time than Rein to deal with it and there's long range damage to deal with him. Rein has no maps outside of King's Row where he is an optimal pick at the moment.
Rein to C, Orisa to B.