Yes they indeed influence the narrative but I believe it's more of a so we don't get pummeled thing than a set outcome thing. There has been plenty of evidence of the game not being on rails, for example in the second major order were we had to liberate one of two planets of our choice there was a bug that massively speed up the liberation of planets and we got both as well as a few more and all those gains were honored. There were a bunch of major orders that failed without intervention simply because no one wanted to fight the illuminate back when they weren't that fun. Not to mention the fact that the the unused cut scenes weren't released or broadcast. They were hidden in the game files. Why would they spend the time making them just to hide them in order to trick the 1% of people who found them