As a workaround:
Global colors, gradients, brushes and pattern swatches are not supported in CC libraries.
But as a workaround you can drag an object using a brush/pattern/gradient/spot or global color to the CC Library
You can also drag multiple items using different brushes/patterns/gradients/global colors together into a CC library to simulate a library.
The easiest way to add them to a new document is to hold down the Alt key when you drag them from the library and place them in a new document. The patterns/gradients/global colors automatically get added to your swatches panel.
You can hit escape before you click to place the object(s) or delete the dragged library items because the swatches and brushes are now part of the document.

I have been using the CC library to catalogue all my assets for projects between machines as intended. however, the lack of ability to store patterns concerns me.

Working with clients and creating patterns is critical. I don't want to have to store the pattern separately or use a clunky workaround.

Please add the ability to add patterns to your cc library.

There are workarounds for this, but it's pretty annoying that the library, in general, has this kind of trouble. There should be a way to store patterns with their name, and then upon retrieval, the swatches maintain that same name in the new File.

I too would like to be able to save custom patterns to my swatch library.

I hope Adobe will soon make it possible to save Pattern swatches directly into our Libraries.
It would make workflow less counterintuitive for many Adobe Illustrator pattern designers.
On the Adobe user forums
https://community.adobe.com/t5/illustrator-discussions/how-can-i-save-a-pattern-in-cc-library/m-p/10688779
2 expert users suggested workarounds.
But we should not be having to work around this still in 2021 coming up 2022.

Patterns are a fairly fundamental aspect of Illustrator. And if we are able to save Objects containing pattern fills into our CC libraries I fail to see why it is not possible to get our pattern swatches saved in there as well.

In AI 2020 and 2021 Adobe improved the interface of basic pattern editing without the need for 3rd party plugins. That is great. Now if you could please allow us to better manage the swatch collections of what we make.

Gradients and patterns can also not be added to Groups (see attached).

A gradient and a pattern should function in the same way colour functions. They are all "fills".

I will also add that even when adding a rectangle filled with the pattern to your library as a workaround so that in other documents you can drag and drop the graphic—that graphic does not bring the pattern swatch into your swatches palette.

It's crazy that this is not possible. Patterns are often very much a part of visual identities. Libraries exist in part to manage and provide easy access to visual identity assets.

https://graphicdesign.stackexchange.com/questions/57904/illustrator-how-to-add-a-pattern-to-existing-color-library

YES PLEASE! :)

Exactly, missing that same feature too!!!

100% agree. Was very surprised to find that I could not.

YESSSSSS PLEEEEASSSEEE.

Yes, please!

Agreed! and you should be able to save gradients as well.