I created a ticket regarding the tooling change on the 500D and how one would go about acquiring the cases that have had the change implemented to which I received the below replies, so it has been confirmed that some of Corsair's employees are not aware of a tooling change. I replied to him with an attached pic of a case without the slot holes and received a second reply, still no joy. So it seems it is just pot luck that you will get a case without the slot holes as there is absolutely no way to identify the cases that have had the change implemented without opening the packaging, color me disappointed.
Response By Email (Nick P) (01/22/2019 05:21 PM)
Hi MAX
As far as I know there was no change to the tooling of the case. Though if there was there would be no way of providing you with information to determine which one was the change and which one wasn't.
Response By Email (Nick P) (01/24/2019 11:58 AM)
Hi MAX
Unfortunately there is no way to determine which case you would be getting.
Another example of how much better the case looks without those awful slot holes.
https://pcpartpicker.com/b/rgxG3C