That hypothesis should be easy to verify by comparing against Belgian French speakers. We have largely the same culture and media intake, but our school system is much less focused on tests.
If anything we have the opposite problem, for budgetary reasons it has become nearly impossible to fail the standardized tests and as long as you get 10/20 it literally does not matter what the score was. I was in the first year when tests were introduced and they were so easy we did not even study for them.
Not since 2020 when Mozilla laid them off. They are now with the Linux Foundation Europe and they accept donations.