Theymos banned only mixers, and Wasabi is not a mixer, it is a CoinJoin implementation.
Theymos may not categorize them as mixers, but literally they are mixers. In short, they are referred to as decentralized mixers.
What I get is Theymos wants to stay away from trouble but he is making some exceptions when it is necessary. Mixers are not illegal, they are important to break your links. Theymos is still soft for a few mixers who are advertising them as not a mixer but basic business model is the same as mixers.