The mixing business is here to stay the authorities cannot make it disappear, there is a dark web where they can freely promote and on advertising here on Bitcointalk so much depends on when authorities start looking on platforms where they are being advertised, and how the forum admin accept these platforms to have a space here in Bitcointalk.
Chipmixer started it all and all the other mixing platforms existing now are just following the thread Chipmixer laid out.
Authorities only get interested to find out and targeting a mixer when there's an incident of hackers sending funds to mix on any mixer platform to avoid getting detected. Say a hack happen on an exchange and the hacker reported to used that specific mixer. This happen to all those mixers who got shutdown.