Well, I can think of many reasons why it would be nice...but let's just hit the main points.
1. Most people who find themselves with 'deleted content' are not thieves and actually paid for what they had deleted. Or it was a gift from a friend and do you suspect every copy/trans present of being stolen by friends? I do not.
2. Someone has to request the deletion for IP reasons and prove it to LL. Logically, that same person would benefit from folks like me who are charmed by the missing item and now would like to buy it for genuine legal copy.
3. Declaring your rights to IP presumes the inventory still matters, even if not available or for sale. Perhaps interest in the item might revive now that illegal copies are gone.
Certainly, there is one person out there you don't want back in your store....but then, that person already knows who you are and knows how to copy your stuff. Keeping your identity from that person doesn't protect you at all.
Keeping it from the rest of us, just seems illogical.
But then, this is all new to me. I was curious. Thanks for responding.