I am sure that you can delete them . when I build EPO4 , I deleted them. becouse our system is windows ,not linux. and when U update the DAT , i think you can choose it , someone is not update . if you update all the files ... it is too large to download.
I delete Exchange /Linux /Novell and other part . and if you make some mistake ...for example , you deleted VSE8.5 , U can check the ZIP file (VSE8.5) , in that case , your client can install VSE8.5 . and you can check it in extention . int that case,you can manage it .