They wanted to showcase all the "exciting" new features they had to offer for Gamescom 2020, when in reality the content they were showcasing was rushed and overall incomplete, it's a matter of marketing. You can't show up to Gamescom 2020 with nothing to show, so you show content that you are still working on with the hopes that you'll be able to finish it within a reasonable amount of time and release it shortly after showcasing it in Gamescom. Sadly the reality seems to be they showcased Modding Tools before they were actually ready for release and so they built up expectations for the community that they unfortunately are struggling to meet.