I went K-12 in WI and we also didn't do graduation ceremonies for 8th grade either. We just took a big field trip as a whole grade class to a theme park and we were all off to HS the following year.
This is how I remembered ending each year...
Grade school K - 5: End of school year Carnival (all grade levels)
Middle School 6th Grade: Science Museum
Middle School 7th Grade: Noah's Ark Waterpark
Middle School 8th Grade: Valley Fair Theme Park
HS 9th Grade: No celebration/ceremony
HS 10th Grade: No celebration/ceremony
HS 11th Grade: No celebration/ceremony
HS 12th Grade: Graduation and Senior Lock-in Night
I think in the midwest, we generally don't celebrate or do a "graduation ceremony" because in 8th grade you don't actually get an academic degree or diploma. I mean, when I walk up there, what are they going to give me?