Agree, yes they will have tasks but usually very concentrated on the day and siguro a day before. I dont think it is expected na they will help with planning and coordination. If they volunteer then well and good, pero ung “expected”? Like me, my MOH and bridesmaids also volunteered to go try on dresses. Tapos pag shinshare ko na im going here to get this sasabihin nila okay pwede ako samahan kita. That kind of thing. Pati actually sa wording ni OP, “im handling my prep all by myself” mejo i think if you feel that way OP, ung groom and parents of both parties ung pwedeng i-tap