The meaning of a word, is also how it is used and what it is use to reffer too, Words can have a primery meaning (the origional use) But Language evolves, and as luanguage evolves so does the meaning and/or meanings behind words.
This is why slang terms are now being included in dictionarys, Giving words extra and/or multiple meanings. Across multiple luanguages.
So given, The contexts in which "cis" was used in the article it means as was described, even if only as currently un-official terminology.