I wonder if this is to make it more inline with a traditional internship, I believe that's about how long my internships were.
it's good to try new things once in a while.
the part time schedule allows participation by a different group of students. it also allows weaker students to participate who may feel they need more time to deliver the expected results. now they have a buffer to do that.
whether that's a good thing or not remains to be seen. but the only way to find out is to try it.