No. He got admitted the same way the Kennedy boys got into Harvard: money and connections.
This is how I imagine Grandma Bush helped - she called the college alumni office, said my grandson had better not flunk and he didn’t. I have seen this before; back in her 20s, a friend applied to medical school - she did not get admitted to the top school in the state but she did get admitted to several other state med schools that were perfectly respectable. She had her grandfather, a doctor and alumnus of the university medical school, harass the admissions and alumni office - to their credit, although the admissions office had to reverse themselves and admit her, they wrote a letter informing her that yes she was now admitted but she should think over how she took the place of someone who would have been admitted on merit. Kind of like GB’s uncle, the nimrod GW, bragging to his father how he got admitted to Harvard Business School “on merit”. If GW got anywhere on “merit”, it should have been managing the town dump. Born on third base, and he brags he hit a triple.