I always assumed that some actors had this capability and acted accordingly. The existence of a publicly available tool merely democratizes this power. Anyone seeking complete and perpetual anonymity should have been practicing better opsec from the beginning.
What opsec measures could one take against language analysis? Everyone has a particular style of writing, and the only way of hiding it I can think of is not writing anything at all.
* Make a small number of posts per account
* Run your posts through machine translation services
* Pay someone on fiverr to write a synopsis of your content, then post that
* Intentionally vary your style, build rich back stories and identities for your nyms, including telltale mannerisms.