Would “services“ count as a product line?

(Just depends on your definition. I think this needs to be clarified here.)

The Apple Car is another possibility.

We have a while left before 2030, I think a lot could happen.

https://appleinsider.com/inside/apple-car

Apple Car | Project Titan, Release Date, Price

Is an Apple Car just down the road? Read more about the top-secret project believed to be known as "Project Titan."

iPhone has hovered around 50% of Apple's revenue for ten years.

The likeliest challenger is revenue from Services, which has doubled to 25% in the past 7 years. In my opinion, their focus on visionOS devices makes another doubling of Services seem unlikely.