The sweet spot for civil supersonics from an aircraft design standpoint is less than Mach 2. You can maintain good propulsion system performance without variable geometry inlets, boom strengths are lower, aeroheating loads are lower, fuel burn is lower, etc. Operating expenses will be significantly lower for such an aircraft. Maybe Boom is finally realizing the importance of all this as well.

Whether that's enough travel time reduction to make these aircraft worthwhile is definitely a valid question. The low-boom technology that NASA is pursuing is for sub-Mach 2 aircraft (I don't believe Boom is pursuing a low-boom design, but I haven't followed closely as I don't consider them a credible organization either).