... why did this change take place?
First of all you should note that about 50 years ago the mass was in Latin language so using the Creed in local language is quite new.
In my youth in the 1980s the Apostle's Creed was already more common than the Nicene Creed (which was only rarely used in that time) so the change you are describing must have begun directly after changing from Latin to local language.
In the parish where I grow up the Nicene Creed was nearly never used in the 1990s. And when I was going to the mass in other cities I had the same impression.
Some theologian told me that sometimes the church law is changed to allow something which is already "illegally" done in many parishes for more than 30 years.
If it is true that using the Apostle's Creed in the mass was not officially allowed before 2002 or 2011 then this change of the church law seems to be one example for such a change.
And I doubt that in such cases you'll find any written document that describes why something is done:
When such a practice begins it is illegal according to the church law. So nobody dares to write some document why this is done. And 30 years later when the practice is officially allowed nobody can remember why and how everything started 30 years before.
I have a very strong suspicion why the Apostle's Creed is commonly used in German speaking countries. It's some ambiguous sentences in the German translation of the Nicene Creed. I can't judge other translations.
Through our Creed, we profess our faith ...
... which means: You are publicly saying what you believe in and you stand behind what you are saying. And this of course implies that you understand what you are saying.
Now let's have a look at the German translation of the Nicene Creed. As an example you'll find these words:
... gezeugt, nicht geschaffen ...
Having compared the English to the German translation I suspect a "simple" translation problem here: The word "gezeugt" definitely does not match what is written in the English translation!
I myself understand the German translation of the sentence in a way that Jesus Christ did not exist at the beginning of the universe but he is the result of a random biological process.
(And this is not the only sentence in the Nicene Creed which I at least do not understand.)
Translation errors in the Creed however are fatal:
Either you say the Creed in the mass - than you say that you believe in something you actually don't believe in.
Or you don't say the Creed (that's what I do if the Nicene Creed is used) - then it will be rather silent in the church.
Maybe this is the reason why priests in the parishes started to use the Apostle's Creed instead of the Nicene Creed in the end of the 1970s in Germany.