The subjects would’ve benefitted equally by the doctors being put in prison for the rest of their lives (or given the death penalty, per Nuremberg) if only to set an example to the rest of the field.
Massive damage was already done to their bodies, but you can still get rid of late stage syphillis with penicillin and prevent further damage.
For what it’s worth, Tuskegee just happened to be the ethical failure that came to mind because it's been in the media recently (in the context of "why do PoC have reticence to take vaccination", i.e. for COVID-19). There's plenty of other examples where the damage was irreparably done [1, 2] where it would be questionable to hand the participants' personal information over to another group of researchers for further study.
1: https://en.wikipedia.org/wiki/Unethical_human_experimentatio...