I'm reminded of a post from a few years ago where someone's website had a table of items with [delete] links and would take database actions based on GET requests to those URLs. Who cares? It looks the same to a human browsing it.
And then it got crawled by a search engine which followed all the links to see where they went.
But if you're not doing anything unusual like that, I don't see how prefetching HTML would cause any problems.