Fowler means it literally. He had examples published on Artima.com years ago where he gives examples of hard coding things left and right and adding better support “only when you absolutely need it”.
To be clear I am not arguing for big design up front. I am arguing to keep an eyeball on your roadmap, and that is not only OK to anticipate the future but maybe do some small amount of work to make the future work easier.
The fallacy of “You Ain’t Gonna Need It” is that you so very often do, and the developers down the road are cursing out the devs who ignored the future.