That link can be found here: https://docs.nativescript.org/guide/code-sharing
Let us know where you got that other link and we can correct it.

Possible right now

In general, allowing NativeScript to grow naturally alongside web specific markup in a workspace is pretty powerful today because there are literally 0 compromises. In a workspace you can drive both web and NativeScript apps with identical shared logic and component mechanics while decorating each view specifically tailored for the delivery platform.
For example: https://nstudio.io/blog/nx-javascript-is-dead

What about singular view markup?

NativeScript markup can be rendered as web (what we generally refer to as the inverse/reverse approach - similar to RN for web) which experiment was done a couple years ago:
https://github.com/NathanWalker/nativescript-angular-web-components

In general, works fine. It's just that you typically want very acute control over web markup specifically where a workspace driven approach provides ultimate control.

Provide feedback

In general, you might briefly outline what you feel would be valuable for your dev building purposes (an ideal) and discuss from there; collaboration with you on such a thing would be awesome, thanks for starting the discussion!