It's hard to say with a ton of variables to be considered. Who is doing it and when and where. And most definitely What are they doing? So I think the potential is plausible, but extremely difficult to actually succeed except for minor changes that ultimately only go so far. Otherwise I would imagine things would have been changed a time or two already. And while the characters wouldn't know if that had happened already or not, we, the readers would. And it clearly never did. Not an angle anyone wished to focus on.