Who knows, it could be temporary. I honestly think it's pretty likely that they will start considering following bitcointalk's steps if they get into authorities' radar-- you know, like being mentioned on their website or something.
I'm pretty sure that the Altcointalk admins are very much aware of what's happening here they clearly stated their stand that they will welcome mixers promotion in their forum, this is a welcome development for the mixing industry and for posters, they could only follow Bitcointalk's stance if there at least two or three mixers that become notorious as money launderers so far all the mixing that's going to make a campaign there next year are all doing good and there are no big issues like what happen to Sinbad.
We never know if Altcointalks become the marketing platform of mixers, we'll know that in the first 5 months.
Admins seem to get preferential treatment in signature campaigns on that forum. There is obviously some quid pro quo going on — it's not that they are doing it for free speech or some other virtuous reason. They have a right to run their forum however they please but it wouldn't come as any surprise if their domain got seized eventually. Participants should be aware that by using centralized services there may come a point where their BTC is considered tainted and will be questioned as to the source of their funds.
While having alternatives to Bitcointalk is a positive thing, altcointalk still needs a lot of improvement in terms of quality. Last time I visited it was full of spam and poorly translated content. Most of their users seem to be from regions lacking in economic opportunities and aren't very fluent in english. It is perhaps not the best place to be advertising a mixer but at this point these services might have to settle with what they can get and hope it turns out favorably.