A carriage is a wagon that transports people, not "things", a carriage are also usually wheeled, just like wagons.
In this case, one reason why "wagon return" might have made more sense is because there is a wagon that holds the platen of the typewriter.
It is a standard engineering term, e.g. https://en.m.wikipedia.org/wiki/Gun_carriage
I said "as much sense", not "more". I am just not used to a language that makes the distinction.
Doesn't seem perfectly consistent in English either. When there is a "wagon train" in a Western movie it is often full of people in wagons. Seems like wagon vs carriage is a bit more complex than just if it carries people or not?
https://en.wikipedia.org/wiki/Covered_wagon