I think this would only apply if you did not get all the worms and their eggs at the time of worming, keeping them on a schedule should where the worms are killed in a timely matter and not leaving any behind to build up a resistance.
This is why we say when you give antibiotics give them as per instruction and don't just stop cause they are getting better cause anything left behind can build up a resistance and you would have to use a different antibiotic next time , if there is one.
This is just how i understand these things work.