People want change in games, especially when said games have stayed the same over many iterations , like Far Cry.
Imagine if the new Zelda played exactly like Zelda 1.
I think certain games are more open to change than others. I tend to think Far Cry in general is gonna be Far Cry. Ubisoft games in general are going to be games with a billion side missions and treasure hunting games until there is a financial reason for them to change the formula.
I think they can certainly improve it, but I expect it to be mostly the same as others in the series. A game like Zelda is completely different. It's an adventuring/RPG game. That formula can be changed up to suit what elements make up various action/rpg. This type of game generally will stay in the style the series is known for. They tried to switch it up with Primal, and it didn't really do all that well (and yes, I know it was a re-skinned Far Cry 4).
Edit:
Also, it's not always easy to tell what will work when they switch things up. With Assasin's Creed: Black Flag, they used ships/boats and naval combat. Most loved it. Yay, success.. cool! Then with the new game coming out, people saw boats and there was more negative reaction that I read than positive despite Black Flag, though, that remains to be seen how that will play out.