I think a history of changelogs, news articles etc. belong to a roadmap, as not everyone will be using the latest tech. Of course it’s also advertising. But you have a valid point.
On that website you can’t really see what anyone is working on. You can’t write a proper feedback. It’s basic journalism and advertising which is for a specific group of people.
However I expect something entirely different from a roadmap. As an active developer and programmer I go straight to Git, the documentation or the changelog whenever I need to. I can’t do anything with a 20 line description of the new lighting system written last month.
If you are a programmer, designer, translator, animator, modeller, name it, there is nothing on the page you don’t already know?
Maybe their idea of that “Roadmap” page is not really aimed at developers?
A roadmap should be the place people go to be informed about current and planned projects, important changes and to get involved. But I would like to deep dive into a proper administrative system to see calendars, tickets, commits, customer / developer / community interaction and feedback systems. I’d like to vote up engine issues which have been pushed aside for the past 10 years leading to constant frustrations on this forum with old and new devs. That is what a roadmap should be.