Originally Posted by Old Dad
I'll agree with posts by numerous others. 7th-8th grade is a GREAT time to explore, perhaps face plant, or at least struggle enough to be forced into learning how to study. Grades in MS have zero bearing on any college application.

No, but they determine whether a child will placed in honors courses in 9th grade, which does matter for college admissions.
In addition, the correlation between grades in 8th and 9th grade must be substantial, so mediocre grades in 8th would concern me.