“The Apocrypha, — such as the Didache or the Shepherd of Hermas — were well read but not included.”
You might want to read up on what the Apocrypha is. Athough it can be used in a general sense to refer to ANY book that has ever been used as scripture, it normally refers to those books found in the Vulgate.
The Council of Trent said the old Vulgate was the standard, but then didn’t list 3 of the books found in the old Vulgate. Oversight or not - I don’t believe there is any record of debate deciding to remove those 3 - it forced the Catholic Church to come up with a new name for the listed books, and to issue a new copy of the Vulgate without those 3.
That is why those 3 are found in English Bibles with the “Apocrypha” - because for at least 1100 years, they were printed as part of the Bible.
It seems Trent changed the canon, although it also seems they didn’t intend to...
Granting all that you say, — I don’t argue over words, —there is still a good reson to distinguish the Deuterocanon from the rest of what the Protestant usage is: the Septuagint and the 1200 years of canon history prior to the Reformation.