I don't know what kind of question here you are implying to.
If you mean by doing that a lot lately then it's because many users doesn't respect and should follow requests rules no matter what, it prevents us to get informed in a better way (in a way for example based on what platforms would like, cheats to be added etc) and that is less time wasting and less requests to manage as you can see it's more than 200 pages.
As for deleting threads i don't do that without proper motive but when it comes to multiple requests on same game i have either to let PM to user as a notification with a link to original thread request or if it's already completed i move both to specific sub-forum (here they will get automatically notification status) so unless if you suspect a thread being deleted for no reason use report form or contact to any staff members and we shall investigate it.