Currently in a 7-player game the computer will randomly assign either 2 or 3 players as saboteurs. Some would argue that the advantage of not knowing whether there are 2 or 3 sabs is that the unpredictability adds some interest to the game--players have to deduce whether it's 2 or 3. To this point, in 2-sab games I've seen diggers going crazy breaking each other due to paranoia about a third sab. Also, saboteurs use this unpredictability as part of their strategy when aiming for a late reveal: "I'm not sab--it's a 2-sab game, not 3". So it does seem that randomizing 2 or 3 sabs has certain advantages for both player interest and strategy.
However, the flip side is that playing a 2-sab game with 7 players or a 1-sab game with 5 players is also extremely boring. It is exceptionally rare for sabs to win in this way, and there is a prevalent sense of resign, frustration, and unfairness. If a win happens it feels amazing, but mostly it's just a lot of sitting around broken, waiting for the misery to end.
Personally, I think an option to choose "max sabs" would be a great addition to the BGA version of Saboteur. It's the best of both worlds since players who believe the random option adds value to the game can still use it while those who think having the minimum number of sabs ruins the game can opt to make the playing field more even and fun for all.