Recently decided to learn typescript. You would hardly know there's a Debian package from reading typescript's website.

Why would the typescript webpage mention Debian at all?

Upstreams often mention distros in which their software is packaged, how the package is called and sometimes even the commands to install it.

They do mention how to install it, it's done via node. To me it sends node are the ones that should have distro specific notes on how to install?

Don't know why the TS team would point to a 3 year old fork of something they don't have control over.

In telling you how to install it. That's kind of the point - they all assume you're going to use npm to install it.

Doesn't seem very far fetched to use a node package manager to install a node package tho?

Maybe not. But I'm not going to if I can help it, which is entirely doable by using Debian's package manager. And I avoid running things as root if I can help it. It's bad enough I need to run apt as root. The recent recent news hasn't increased my trust in npm.