Trust/ Probate/ Holographic will

Heres my situation, my father recently passed away. He has a revokable trust that im guessing my step mom created because it basically cuts his four kids out completely, im imagining he signed on to this because he was first didnt want the confrontation, as well as he didnt want her to deal with another divorce and her taking some of his money because they had been married in california for a few years. He always had to tip toe around her when it can to spending his own money, she watched it like a hawk. Years later he created a holographic will and has pretty strong notes on it saying how the current trust is revoked, because it basically leaves his kids out of everything besides for a very small items. The holographic will is signed, dated and explains the it is willed to his children. I am wondering if this would go to probate. Step mom isn't really acknowledging that it has any grounds.