score:3
Ludwig Ott, Fundamentals of Catholic Dogma (Book 2, §14), directs us to relevant councils:
The first of these rejects the idea that man has "two souls," which, if not completely rejecting trichotomy, at least gets close to it. Canon 11 reads:
The Old and the New Testaments teach that man has one rational and intellectual soul, and all the Fathers speaking the word of God, and all the teachers of the Church declare the same opinion. (Denzinger, §338)
unam animam rationabilem et intellectualem habere hominem (Ott)
In the opening chapter of the 4th Lateran Council, we find a more explicit statement within a general expounding of God's nature and creative work:
By [God's] own omnipotent power at once from the beginning of time created each creature from nothing, spiritual, and corporal, namely, angelic and mundane, and finally the human, constituted as it were, alike of the spirit and the body. (Denzinger, §428)
deinde (condidit creaturam) humanam quasi communem ex spiritu et corpore constitutam (Ott)
So it turns out that the trichotomous doctrines were only officially rejected several centuries after Apollinaris, but still well before the Reformation. Thus it makes sense that many major Protestant traditions continued to hold this view.