in 1997, Steve killed the Newton because Apple was close to bankruptcy, but said it will bring it back.Meh, no big deal. Dell has a ten-year pipeline full of products, and I have a copy. See:
Oct 2011: Introduce model with faster Intel chip
Jan 2012: Introduce model with more RAM
...
Jul 2021: Introduce model with faster Intel chip
Sep 2021: Introduce model with more RAM
See? Brilliant!
Apple started working on the iPad in 2000 and it was introduced in 2010. 10 years in the pipeline. So four years is not so long.
In 2000, when somebody showed Steve the spring movement at the end of a list in IOS he said he would be perfect for a phone, they stop working on a tablet and switch to iPhone. Another product that stayed 6 years in the pipeline.
4 years mean that some of those products are well advanced in the pipeline.