The coins are now in several hundred new addresses with 300-2000 BTC each. If it's actually using the splitBigOutputs() function they should end up in 30k different addresses holding less than 10 BTC each.
the more the coins are handled the more foot/finger prints are made visible and the more connections could be made
for example, in order to mix you must go to a mixer their computer records will show the coins going in by x isp at y timestamp
that mixer will either cooperate or be materially embroiled in a criminal investigation
now with that isp as the finger print you could look for other places where that isp has engaged other mixers, exchanges, etc ...
eventually the electronic finger prints and foot prints will lead to humans who will need to explain. If the prints are MK, MG employees, and or relatives of either arrests would be.
whatever "mixer" it would be - it would have to have an at least about equal amount of BTC at the time of mixing to be able to cover any tracks... If 200K + 1K per day go in and 201K go mixed out, this is quite traceable, too.