The 'new stuff' is split into two categories:

1. Better, real-time atmospheric data that allows use of boom-refraction flight profiles to prevent the boom reaching the ground. This is a trick that Concorde sometimes used when conditions were right, but only works up to about Mach 1.2. This is what Boom used for quieter flights.

2. Crazy 1950s-style airframe shaping with the X-59 that reduces boom but is impractical for an actual commercial transport. This is intended to establish a baseline for tolerable routine boom intensity, but we don't yet know how to make a commercial airframe with the same quietness.

Nothing is really new.