The big problem with Concorde was that it wasn't allowed to fly supersonically over most land due to noise restrictions. Thus eg transcontinental US, where the time gain might have been quite attractive, was ruled out. The same issue combined with limited range also ruled out nonstop London-far east (Singapore, Hong Kong, Seoul, Tokyo) or London-West Coast US. Are these issues likely to be any different now?
Also - not sure what you call Mach 1 class but the business jet market has a lot of planes which will cruise at eg Mach 0.93 or so - ie faster than airliners - and speed is valued in that market. If noise issues over land can be navigated successfully then I would expect there is a good market for supersonic business jets.
London to Tokyo great circle looks like it doesn’t cover much human habituated areas, especially if you modified it a bit to go around Norway. I think if fueling allows, you could come up with routes like this for many potential trips.
Norway may be scarcely populated but if you piss out the few people living there they will make pressure to their government which will forbid flyovers. I don't think it will be hard for them to argue that entitled business people having to quickly travel the other part of the world have no right negatively affecting their quality of life.
Also - not sure what you call Mach 1 class but the business jet market has a lot of planes which will cruise at eg Mach 0.93 or so - ie faster than airliners - and speed is valued in that market. If noise issues over land can be navigated successfully then I would expect there is a good market for supersonic business jets.