SR4 explicitly stated "Each tradition can master five types of spirits." In SR5, there was a big implication that you were restricted to only the 5 spirits of your tradition, even if it wasn't explicitly stated. However, the UMT ability that we got late on in the edition was very explicit about adding a spirit type, meaning that in fact as far as that book was concerned, the RAI indeed was 'traditions only get their 5 types' and the lack of explicit statement was a mistake. So Stainless isn't right, the complete release of Spirit-type-tradition-restriction is an SR6-specific thing.
That said, I rather like that tradition is more a matter of roleplay rather than a game-balance thing. In previous editions Shaman and Hermetics were actually both inferior to some other traditions, due to the spirit-types.