Theresemt
If tickets are sold now with an expected arrival in Zurich at 10 am and the train is rerouted due to construction works and arrives at 11 am, you can obtain a refund of 25% of the ticket price. If it arrives at 12 pm, you can obtain a refund of 50% of the ticket price.
It is understandable that they are waiting to know the final schedule to sell tickets and avoid these refunds.