I sort of agree with you, but that would create chaos with team's scholarship situations and it would mean that all of the weights next year would be UNBELIEVABLY stacked! 133, for example, even without allowing seniors to return, is going to be INSANE next year. Medaling at that weight will be a major accomplishment--an eighth place finisher at that weight next year, even without returning seniors, is going to be a challenge for really, really good wrestlers. Think about it:
2020 133 lb. seniors possibly given extra year of eligibility:
Charles Tucker
Travis Piotrowski
Seth Gross
2020 Olympic redshirts returning:
Dayton Fix
Nick Suriano
Stevan Micic
2020 underclassmen returning:
RBY
Austin DeSanto
Sebastian Rivera
Mickey Phillippi
Even without allowing 2020 seniors an extra year, 133 is going to be loaded. With those wrestlers back? The match for 7th/8th would probably have better wrestlers than some other weights for 3rd/4th. And that's not taking into account relatively unknown young wrestlers who might improve dramatically next year and become part of the mix.