I don't see how you could possibly come to that conclusion. I've always told people before hand (because it makes sense, not because it was advice), and I've never immediately (or ever) regretted doing so. Who said he wasn't going to do his best? Of course he will. But why not do his best while giving people an understanding of what they're about to hear? Stuttering is very distracting when you don't expect it - especially since I can guarantee a lot of those 2k kids will have never encounted someone who stutters. When they're aware, they'll pay more attention to the words themself.