RPG dialogue trees having several different options for saying the same thing is nothing new. I'd personally argue it's even desirable
since it allows you to build your own image of how the character behaves. The alternative is being a passive onlooker watching characters talk, while this at least allows to do some roleplaying.
In this case, option 1 would be the more confident/enthusiastic response (promises success) while option 2 is more reserved (only promises to do what they can). Most of the time dialogue options are not about making constant "meaningful" choices, but keeping the player as an active participant while allowing them to season the conversation with small variations.
For example in Dragon Age Origins, after the prologue you are forced to join an order for the rest of the game no matter what you choose. The plot would never move forward if you didn't join. When presented with the offer the dialogue tree offers you not one, not two, not three but four different ways of saying "Yes":
1. I would be honored.
2. I accept.
3. Well, I can't see as I have much choice.
4. If it gets me out of the Deep Roads, I'm yours.
Three Houses is already promising to have a major(?) route choice with three options, which is more than most games that are not VNs or choose your own story-adventure games. If anything they are maybe being a bit too ambitious with their promise of choice.