I have read/learned here at PB that...

(I'll paraphrase) IF a fish looses a season of being well fed, it will loose that growth spurt and will not recover it before it's demise.

A stunted fish population is typically the result of too much competition for food due to an overpopulated pond. Those fish have lost that "season", maybe more, of being well fed. Those fish will continue to grow once the overpopulated condition is fixed, but they may not see full growth potential.

I suspect their offspring, given an improved environment, will have the growth potential you would expect. Of course, good genetics can make a big difference in trophy fish results, but I do not believe that stunted fish pass on stunted genetics.

Fish on!,
Noel