The reason why can be seen at the end of the deletion log excerpt within ( ). Here it was: (empty category and no further attempt to add something).
As written in the wiki forums:
Empty categories and pages get deleted after a short time. That's part of the regular clean-up!
Often user create pages because they wish a work to be added here (instead of making an entry in the wishlist / forums), sometimes pages are created erroneously, sometimes with a typo. Other users just create a composer category because they want to show a picture but don't want to upload anything, sometimes duplicate pages are created.... etc., etc. Also, we are a library, so there must be at least one file on a work page, we don't want to have 'an empty shelf'...figuratively speaking. There were already cases where users created pages, disappeared then for some weeks, came back, created again the identical (empty) pages, and vanished another time.... sorry, but what's the point of that? I mean, why should I create something and not upload? Then I simply must take my time. Anyway, hence such pages are removed usually after 2...3 days, otherwise we can't to keep track of all the empty stuff. There are other admins who have deleted emtpy things after 24 hours, btw.
There are only few exceptions of empty work pages (e.g. of copyrighted works, where people have repeatedly created these pages or tried to add stuff) as a reminder with a clear copyright notice.
Please create the category again once you have time to add things.
Or let me know, then it can be restored, of course.