The entire initiative is based on the idea that it is more friendly to route around contrails. I work actively in this area on the routing side (flightscience.ai), and can assure you it's actually fairly cheap climate-wise to reroute a flight given enough warning. If you check out their map (follow TFA's links), you can see that contrails are formed in fairly localized areas.

Go to aviationweather.gov, and you can see huge boxes of alert areas that we already have to deal with. It's really just another day at the office.