Why shouldn’t he go?
Is he banned from competing? If so is the ban for a specific length of time or is it pending the outcome of hos case?
Does he plan on competing in the Olympia in the future?
If he is banned from the contest showing up would be a defiant act. This could likely lead to him being blackballed from future contests. Even if he is found not guilty of the charges and his actions are shown correct he could still be seen as willing to make the contest about himself instead of "trusting/honoring" the actions the leadership has taken.
He would be fighting the establishment ala Kaepernick and it could cost him his career.
If hes willing to pay that price/take the risk he should go.
From a pr standpoint he should take the ban and site the innocent until proven guilty line, be the victim in this case and win over the portion of the fan base that has abandoned him.