This is for everyone still looking for an answer to this thread.
My deleted adobe library was recovered.
Heres the story. Back in June, 2020 I was frantic after I realized I deleted my clients Adobe Library. This library easily had hundreds of hours worth of collective work from my team. This was not deliberate on my part, but rather miss understanding with the adobe stock asset website. On stock.adobe.com I was puzzeled to see my clients library contain zero items. (Later I would understand when viewing your libraries on stock.adobe.com it will only display saved or purchased stock items.) So when I saw an empty library, I assumed it wasn't needed, so I deleted it from the stock website. When I returned to Illustrator I realized my clients library was missing (deleted). After my sinking heart started to pump again I took to the interet to see if I could find answers. I read forms and perfored every suggestion I came across. Checked the online "deleted" section. Looked into backup drives on my hardware (which was a promissing solution but I neglegted to backup frequently). I worked with adobe support, created tickets and had phone calls which ended with reduntat suggestions and a guy who hung up on me.
So how did I get my deleted library restored. I went to social media. On facebook I sent Adobe a direct message. I wrote about my situation, stuggles, and hoped they would help. In my luck, the marketing team at adobe read my message and they stepped up. They had a call with their developers and were able to manually restore my clients deleted library. They too agreed that library restoration should be a feature for the users. It was never mentioned they would role this out as a feature in newer updates, but I hope this can be useful for anyone reading this who finds themselves in a simular situation as myself.
Recover Library Assets from a Backup Drive
If you are great about performing backups, your in luck to get your library assets restored. For Mac users using time machine you can locate your library assets on your external drive at:
/Users/yourname/Library/Application Support/Adobe/Creative Cloud Libraries/LIBS/1010101010101_AdobeID/creative_cloud/dcx/101010101/components
Hope this helps