Hi,
Please see
https://vborg.vbsupport.ru/showthread.php?t=142913 , where all of your questions will be answered and concerns addressed.
To summarise it: The threads are not Deleted, they are currently in a forum that is not Public. There may be a change put into place that will allow people to read the 'deleted' Modification threads without being able to download the files.
As the discussion is already taking place in the thread I linked, this one shall be closed.