The way I look at it is this: The first chunk is likely done, from a developer standpoint. Why bother redownloading that just for the new content?Yet another effort wasted by a dev who either hasn't discovered or won't use upload sites that allow larger than 5 GB uploads (like Gofile). I hate games going to a second file due to size. They almost always cut to a point before what I'm actually here for, and they never work right.
I realize that FatGiant is likely right on why the devs divide the game up they do, but my thought just feels (at least to me) like a bonus for players.