I have this bad habit of keeping the old versions of the Nikon Z lens roadmap over the last several years. In 2019, they added a 60mm and 105mm S macros, but in 2020, Nikon switched the 60mm to a 50mm, which was formally announced in June this year, along with the 105mm S. Both turned out to be f2.8. The 24-105mm S has been on the roadmap for a couple of years, all the way to another version of the roadmap earlier this month when Nikon announced the 18-140 DX. Perhaps initially Nikon had a 24-105 in mind, but I am sure they had known for at least a year or two that they were switching to 24-120 S. You need to ask Nikon why they didn't update it earlier. You would think 24-105 vs. 24-120 is not such a big secret that they need to hide.