That's the whole point of also mentioning GNU. The kernel Linux is also used to support other systems than GNU, such as Android, ChromeOS, etc.

If you expect the typical Bash user environment, then any GNU system will do (also Cygwin for instance). But don't look into Android for that. GNU and Android different systems that both happen to run on Linux.

I had never read it before.

The idea that there's a civil war in Ukraine comes from Russian propaganda. There's actually a war against Russia going on there. The people who initiated it and the people on which it relies today all have Russian citizenship.

This makes a lot of sense actually, because the hardware support of the regular kernel often doesn't cut it for newer systems, while the rest works perfectly fine when you have an updated kernel. There are even kernel backports provided in the regular repositories for this reason. The same is planned for the X.org server to keep up with hardware support.

Jitsi should do all of this.

Maybe we can expect a version of IE for Android soon? :D

Not Chrome or Chrome's source code, but there is Chromium with its source code. This is also what I'd use, since it's in Ubuntu's repository. Why would you want to use Chrome instead of Chromium?