I don't think being uncivil to uncivil people furthers the cause of civil discourse...I don't claim to practice what I preach and I understand the difficulties in this case, though.
Talking about native speakers is not the right way to frame the debate – there is only idiomatic and unidiomatic, right and wrong usage.
The English language doesn't belong to anyone.
As to the question, it's a coin flip between:
1) "Ce sera droit" (small d): "That would only be the right thing to do!"
"Qui agit honnêtement, qui est franc, loyal, honnête : 'C'est un homme droit' "
here "droit" = "right", ref. Daryo
2) "Ce sera Droit", capital D, this will/would be a correct interpretation of the law > "Let justice be done" (Andrew)
here "Droit" = the Law
It's interesting to note that the term bewildered a Francophonie law website:
"Haïti, Cour de cassation, 1ère section, 04 juin 2014
https://juricaf.org/arret/HAITI-COURDECASSATION-20140604-RG6...***Ce sera droit »* (Sic) ;. ATTENDU QUE le juge a fait droit aux demandes***"
Given the reference immediately above (=> usual norms not applicable), and given that I've taken Daryo's answer a lot further, I will post an answer.