While the idea of language literally changing the way you think is probably not true, I think the weaker version of limiting the thoughts you can express is still interesting. What's the use of having revolutionary thoughts if it is literally impossible to articulate them in any meaningful way to anyone else?
Anyway, while the book is a cautionary tale, it's still science fiction at the end of the day. Orwell can hardly be blamed for people taking the Newspeak stuff too seriously.