With these services shutting down, it might disrupt their business until they can find another source of liquidity to mix with or they change their process to not be dependent on third parties. It could also be that they got spooked by the recent arrests and decided to shut down before the same happened to them.
Shutting down without making users and affiliates whole is called an exit scam. It has happened before with the likes of Bitblender.
In the case of users, we don't know if anyone sent coins that have not finished mixing when the sites were brought down.
At least Unijoin was well-ran enough to automatically open affiliate accounts upon creation so that I could withdraw my commission from there, but from both a privacy and business perspective I am definitely not looking at this with enthusiasm.
I completely agree, as long as they don't provide a solution for the case of your money still being stuck on their site then it can be called a scam, whatever amount of money is still stuck in your account you should be able to make a withdrawal. It's a shame that the name of such a big mixer is ruined because it doesn't give you your money. Hopefully the developer will immediately activate your account and be able to make withdrawals from your affiliate results.