Mach 0.95 does not get you there "Much quicker". Especially not with ATC issues and a very high cruising altitude. Those descents and climbs are going to be slow. If an airline streamlined its check-in and customs procedures, it could still beat a Sonic Cruiser 'from arrival at airport, to leaving airport at the other end'.
And a half-hour saving across the pond will never replace Concorde.