Language and Communication
This quote is true in a way. Yes words will be cutout of the dictionary but are they really cutout of language? And is changing language really going to banish thoughtcrime? Just because words are being narrowed and people are not going to use them dose not necessarily mean that people wont think them in their heads. People will be trained not to use certain words but you cannot train someone to not put those words in their head. A humans mind and emotions are something that can not be changed just by slowly removing words from existence.
"By 2050, earlier, probably - all real knowledge of Oldspeak will have disappeared The whole literature of the past will have been destroyed." (1.5.30)
Soon, as generations pass, people will not know what Oldspeak is. I believe that is a true statement. On the the other hand you don't need Oldspeak to feel emotions or to think to yourself. Just like in the story, If a young man and a young woman meet and fall in love in 2050, they will still have feelings for each other, feelings that would be considered a thoughtcrime. Even though there are not words to express the way the feel they will still feel it.