What you are saying is correct but to me the real lucky states aren't necessarily the ones with mandates to only accept IS applicants.
A school like Brody with a strict IS bias only accepts around 150 applications out of 920 spots. Likewise Southern Illinois only accepts 140 out of 1200+ applicants(although a good bit of those applicants never had a chance being from northern Illinois). Mercer gets over 1100 applications for 100 spots or so and I believe only accepts 180. Medical College of Georgia interviews around 36% of applicants which while relatively high isn't anything extraordinary.
The REAL lucky ones are the ones that favor IS but don't only take IS. Why? Because most of their applications as a result don't come from IS and that's what makes the competition easier for the IS people. To me the REAL lucky states(aside from Texas) are the obscure ones that don't have tons of applicants. Nebraska, Kansas, WV, Iowa, Missouri, Misissippi, North Dakota, South Dakota, Nevada, Arkansas, Alabama, Louisiana, TN, SC, Oklahoma, NM type of states(I probably missed 1-3). These are where the schools that boost 60% IS applicant interviewed type stats. The thing is these states combined only take up 15% of applicants from the US who apply to med school, so in some ways you could argue they alone necessarily don't really skew the AAMC table all that much. But alas, we're getting ahead of ourselves I just wanted to point out that the states that are truly lucky are the ones people often overlook.