Well, they (Boeing) won't stop trying. SST, HSCT and now Aerion? Aerion has been at it for a long long time. First flight by 2023? Maybe. Certification by 2025, yeah right. They would have to suffer through endless rule making (special conditions), which would unlikely be done by 2025. Good luck with that, the 787 took that long.
https://www.seattletimes.com/busines...2019&utm_term=