Locals have always been allowed to quit the new job on day 1, and it has never been a crisis for employers.
A company that is confident it is offering worthy salary and career should have no extra reason to worry a foreign worker will quit during first week, than that a local worker would do the same thing.
The only difference a fee would make under such conditions is that locals become cheaper to hire, which is the point.
Part of the proposal is that the employer pays the government a large fee to sponsor the visa. They're not doing that for local workers; it's an entirely incomparable situation.
A company that is confident it is offering worthy salary and career should have no extra reason to worry a foreign worker will quit during first week, than that a local worker would do the same thing.
The only difference a fee would make under such conditions is that locals become cheaper to hire, which is the point.