There will not be any interactions between filler and waxing other then possibly temporary swelling. Please keep in mind that each injector may have different protocols for each patient.
Each injector will have different protocols for post treatment care. Many injectors will advice the acceptability of having your lip waxed if you are not experienced any post treatment complications such as bruising, swelling, or cold sores. Consult with your injector as he or she understands the scope of the surgery and the specifics about you.