A lot of store have seasonal products.
Instead of adding them and enabling/disabling them manually every season (if you hide them) or when you are about to roll out a new product line you have to enable all products manually.
I strongly believe in automation.
A publish date feature would be able to set when the category or product should be available. This way you can enter 100 products before hand and publish them on a later date automatically.
The same way would work to unpublish them.
I think this would be a great feature and very helpful for those who are doing stuff ahead of time.
And more automation would help the store display products. You can do random featured products per category. Or automatically related products as “We recommend” feature, based on what category and settings have been made by the user. I have this feature on my current store and all my orders value have DOUBLED.
Same principle would work for promotions, CMS pages etc.