I think he is usually more unpredictable than predictable, and people saying otherwise are just not being honest, because it's always easy to say looking back things like "yeah, I totally expected this to happen".
Whether you like the twists or not, it's factual that Oda is unpredictable.
No one expected Gear 5.
Whether you like it or not, that's another question.
But it was unpredictable, and no one expected such a power up after 1000+ chapters.
But there are lot of dishonest people who won't admit that Oda is unpredictable