oh i hear ya on that, i noticed the little changes to the script in that leaked scene, even when pennywise was saying there was balloons, peanuts, cotton candy, etc. I think in the old script Pennywise also says something like "cotton candy, peanuts, elephant shit" for some reason lol. I'm glad they didn't go with that. So I'm definitely expecting a ton of surprises.
Yeah, the cursing there seems like a small thing, but it's important to note that, in the book, Pennywise can be and is quite lewd. Depending on who he is interacting with, what the true purpose is behind the interaction, he slips behind a lot of different personas (which I believe is what is influencing Bill's take on the character -- the idea that Pennywise has a lot of different "voices" is actually a very keen and analytical take on the premise of the book's version).
So, in some instances, Pennywise can almost be endearing, such is the case with the scene with Georgie. It's one of the few cases where Pennywise is not an overt evil, and the language he uses there in the book is important -- and cursing is a part of that characterization, and I think Cary's take was... this is how kids talk, so why not use that language? And it's a fair point, and could definitely work for a slightly different interpretation of that character, but it is a different character.
In some cases, Pennywise is actual downright racist and uses extremely foul language in the book. He does this to taunt, and reduce his victims in certain cases, and as the power of the kids grows, there's a change in his persona there to direct threats. So that escalation, to me, is important, and Fukunaga's version of the script, with the expletive, I think sends you down that path earlier. It doesn't fit with the tone of what the scene is trying to accomplish.
There is plenty happening of course that doesn't come from the book. And that's fine, and there will be many instances of that. But I think they are trying to avoid changes to the characters that redefine them even in their new context of the 80s and so on, whereas Fukunaga's version, I don't think he cared about making sweeping changes, because he wanted ownership over the experience he had when interpreting the book.
TBH, I'd love to see his version, and I'd actually love to see what Will Poulter would do with the role too (If you've seen Detroit, you know he has a real presence), but I am happier to have a movie that stays between the guard rails in a lot of places, because IT fans don't *really* have a Marvel's handful of reboots to select when they want to see IT on the screen.