I also think that your post is complete nonsense. It does not help at all, so why do you guys have to post this s***?
While it is hard to understand what you actually mean because of your style of writing (it's not criticism, maybe english isn't your native language), I have an idea what you mean.
In the past it was for some strange technical reasons possible that slots at an airport get overbooked, e.g. even if they were only 5 slots available, 6 movements used the slot. This meant, that even if you cancelled a flight, the respective slot still showed fully used which of course seemed strange.
As far as I know (anybody correct me if I'm wrong) there was an update last December where the slot calculation method got updated as well, so it might happen that slots get newly calculated at an airport for any other reason, leaving you with a suddenly fully used slot, even if you operated the same flight in the past. This is a one-time event, so once this happens, the slot calculation method is correct and it will not happen anymore. It's a bit unlucky, but in the end it corrects a bug from the past.
I couldn't find the respective topic anymore (so much about the search function) but I'm pretty sure I've read about this.