Until your appeal is concluded, your eligibility to graduate is determined by your published examination results.
If you are a postgraduate student and your published result was to be awarded a Diploma, you would attend Graduation and be granted a Diploma of the University. If your appeal is subsequently upheld and you were awarded a Masters degree, you would receive a replacement certificate on return of the Diploma certificate. You would not be invited to attend another Graduation.
If you are an undergraduate student who has been awarded a degree but is appealing against the class, there is no impact upon your attendance at Graduation. The class of the degree is not published in the Graduation programme, but you would receive a new award certificate if an appeal was upheld.