This can be dangerous advice. The likelihood of being accepted to medical school while enrolled in an SMP varies significantly from applicant to applicant. It mostly has to do with the competitiveness of the individual's pre-SMP stats (with the SMP performance playing a role), but even then there are not hard and fast rules or cut-offs. Some applicants need an entire year in an SMP before medical schools will even look at them. If you're in a position where an SMP is necessary, the prospects of having a gap year should never be ruled out completely.