I think your analysis would apply to a kid at any size who does not come up thru the kids program. I would say frustration from losing on a regular basis is probably the number one cause of a wrestler dropping out at any level. Yes they are behind when they first come out in high school but it is possible to still be successful. I believe it is possible for a good athlete to become a pretty decent wrestler even if they start in high school. I believe Matt Baker 189 SM East is another recent example of a high school football player athlete who started wrestling in high school and is now a state placer as a junior and a regional champion last year as a sophomore in his second year of wrestling. Actually I would think since so many have said that the heavyweight depth quality is down that this would actually make it easier for a good football athlete to break in and have some good success in comparison to the 125 to 152 range.
I like your idea about bumping up 215 to 220 but only if they added one heavier class. At this time if they were to add one heavier class, I would actually like to see 189 dropped to 185, add the class at 200 and then bump 215 to 225. So instead of our current four classes at 171, 189, 215 and 285, you would have instead 171, 185, 200, 225 and 285.