Have you ever heard of anyone left back over standardized test scores even if they have good grades?

Ma has been using standardized testing requirements for graduating for a couple of year now.

No. How the tests are used is different from school system to school system- ours starting counting them as 15% of the students' grades- but that still wouldn't be enough to fail a student with otherwise good grades. 

No. Standardized test are more for the school’s and general public info.  To see how the school student do compared to other students in their state and across the country,

If a good percentage of the school’s students t get good grades but have scored low on a standardized test, it can mean they have grade inflation.