(Most of whom, I suspect, will be reading your resonse in emails and won't bother to check if you said anything else to other people.)

Unless they read the story again from the same location, which they're more likely to, if they re-read. I do that all the time, especially if I don't have any more feedback to respond to myself *g*, I have the time, and there's been nothing new posted for the fandom I want to read in.