eBay has indeed made some changes and eliminated many smaller subcategories in the Collectibles group and other categories. Lots of sellers (and some buyers) are not happy with the changes. eBay apparently thinks that the changes will make things work better in the long run despite the disruption.
In most cases, you should be able to list in the larger category that the subcategory was contained within. Some smaller categories have been replaced with item-specific filters. So instead of going to the "cookbook" category, users put the term "cookbook" or "cooking" into the search keywords and search.
Not everyone searches by choosing a category and browsing. To make it easier for buyers to find your items, be sure to include the keywords in your titles and include item-specifics that your customers are likely to look for when searching.
