The styles for the chat and dropdowntree are present in the latest kendo-theme-default (v2.54.0). You can always verify the content by browsing the package via unpkg --https://unpkg.com/@progress/kendo-theme-default
. Here is the all.css file: https://unpkg.com/@firstname.lastname@example.org/dist/all.css
. If you search in it, you will see the chat and dropdowntree styles present.
As for the reason why you are no seeing the updated files, could it be, perhaps because you have a package lock and it's preventing you from obtaining the latest version without explicit npm update? Or if you have referenced the npm package via github repo...
Could you try to create a new empty npm project and install the theme there with npm install @progress/kendo-theme-default --save-dev (per say). If the theme installs correctly, then you should probably look at your package.json in your project.