Hi,
Oily skin is often the precursor of acne although not all persons with oily skin develop active acne. It is important to treat active acne first before considering acne scar treatment as active acne will rapidly undo all the benefits of expensive acne scar treatments, makes acne scar treatment more painful and may even complicate healing after acne scar treatment.
But it is not necessary to treat just oily skin per say (without active acne) before treating the acne scars.
Simply put, oily skin has no significant impact on acne scar treatment outcome.
Hope this helps!