This is a way to trigger Panic Mode even though it isn't mentioned in the Release notes here: https://vrchat.net/release or in the recent Developer Update here: https://youtu.be/te1FRAiOMQs
This key combination occurs often and causes Panic Mode by accident often too. Since this key combo isn't documented I think it is a bug that should be fixed so it doesn't activate Panic Mode anymore. It usually happens often because you might be holding something and then press escape to open your menu.