Well this is both “correct” and wrong simultaneously. The Final Cut, which is the canonical version, states that Deckard is a replicant.
However if you watch 2049, that is specifically a sequel to the non-canon theatrical cut. So the statement would be incorrect in that instance.
Newspeak would be an attempt to prevent any language that hinted at things deemed “bad”. For example, we couldn’t call this “fascism” with Newspeak because the approved language would remove that word completely. Newspeak isn’t just changing how you say things, but preventing unapproved behavior entirely by saying those things don’t exist.