Yes, the files will not be available in the repository anymore. There are different reasons behind it (and the main one being that we were updating a log of minified files on a daily base, which led to the repository being bloated with unneeded changes).
There are different ways of downloading all of the files, the best and simplest one is downloading them from our CDN. there is no need to use jsdeliver, we have an updated CDN for you 
Setting up the repository for build shouldn’t take long (apart from the time it takes for the repo to clone). If you have node 12+ and npm 7+ installed, it is (theoretically) as easy as:
- clone repository
- run npm install
- run npm build:umd
- run npm prepare-snapshot
All files will be in the .snapshot directory
Once you have the repository already cloned you only need to run the last 2 steps next time to get the files you need.
Also, running npm install babylonjs in a new empty directory will work perfectly as well. It will pack the files in the node_modules directory, but otherwise it is the built version of the package that you are looking for. local and ready to be used. Run npm update babylonjs in the same directory, and you will get the latest stable version (if any is available).