It feels like a long time waiting for the new MotoGP season. I don't read much news about the development with the factory bike. But I think tomorrow Ducati could be a big threat to the defending champions. Ducati just provides a setting that suits the rider. I'm sure they're confident for next season. They have good motorcycle capital and 3 consistent riders in the top five of the championship class. For Yamaha it could be that they will lose to Ducati if they don't make improvements in the engine, as you said.
Some time ago at an official test I read that Fabio was complaining that not much was happening with the development, especially the engine is still at the same level as last year. Ducati had made a huge step in the last few years with the chassis, the engine was very strong in the last few years, only the handling was difficult.