I'm quite interested to see how this improves the farebox for Fernverkehr. D-Ticket is so ridiculously good for last minute travel that I will change my destination based on where I can get to from my home, even with the time penalty being on a slower train (looking at you Teppich RE Berlin - Dresden). This might tempt me back to Fernverkehr for extra trips especially if it can match or even beat Flix prices.