A few years ago I was talking to a vehicle manufacturer about a fleet order of 10 vehicles that was delayed. We knew each other really well so he admitted to me that they didn't have steering wheels in stock and the supplier was in Italy and they had the entire plant shut down waiting on steering wheels.
The trucks were getting built and delivered in 6 weeks back in Oct/Nov/Dec so it wouldn't surprise me if most of us who are waiting have a similar feature like air suspension, MFT, rambox, etc. that was holding things up.