The article actually talks quite a bit about the additional challenges introduced when approaching Mach 1. Agreed, though, that additional regulations regarding those speeds weren't discussed.

It only really discussed the challenges from the plane's perspective, not the people on the ground when the plane broke the barrier.

The regulations are in place because sonic booms can be not only a nuisance to those on the ground, but destructive.

Exactly, this coupled with it's very limited range kept it from taking anything other than east-coast to Europe routes.

There is work being done on boom-less supersonic planes.