It is still a problem, it is stuck now for at least 20 minutes trying to download package_teensy_index.json.
There is no way the IDE should hang getting started because it can't find something on the external network related to software versioning. At the very least it should time out and move on.
So this is a bug, or a design flaw, and a very serious one.
Please guys, let's get our act together. People rely on the arduino ide.