Hurm dont think the file is that big. I got my copy this afternoon, left it for install for maybe around 30 minutes and can play already, Unifi 5mb user, dont think 4gb download would finish in 30 minutes. But I always check and let the launcher update if there is any before the game release. Also check prior to starting the game there is no background download whatsoever.

Edit : I installed using the disc via setup menu of course