The issue is, if we are writting from 2020, we may publishing in 2021 or 2022. In the meantime, there may be lot changes in the technology that we are working on. So we may have to change lot of things in the book content even we finish all the chapters. This happened to me always. The version of software framework (ROS) is changing and to keep up the new version I will keep on changing all the chapters ( mainly commands and all).
Thank you! :) I totally get it. Same with my book: a new revision of the standard (Fortran 2018) was published half-way through the writing. However, thanks to the glacial pace of the Fortran standards development, I was able to plan for the additions to the language from the start.
All the best for your new book :)