Equality and equity comes into play in giving people a shot. Merit comes into play when it's time to choose who gets the prize. Of course the qualifications for the merits have to be defined. I think what's muddying the argument here against merit is factoring in privilege when speaking of the topic.
In terms of helming a film, regardless of one's race, gender, belief, social status, etc., anyone should have a shot at it BUT they should come with the proper merits within the scope of cinematography at the very minimum. Equity/equality and merit should all be present in fulfilling a specific role. Even the right to vote has merits that need to be met (age, citizenship, criminal status, etc.)
We don't really know if Obaid-Chino is the right person for helming this Star Wars project. There are already aspects working against her favor whether by consequences of her actions or things entirely out of her control. Only the end product will show this. Unfortunately, some may have made up their minds already. Had Gilroy's sentiment of not being a huge Star Wars come out prior to Rogue One releasing, I think he would have found himself in a similar situation with the success of Rogue One possibly getting hampered in spite of its content.
