It’s not entirely nonsense. Not all fake news is social engineering but almost all social engineering has some ‘fake news’ component.
If you can use NLP for detecting social engineering scams, it can also be used to detect fake news. There will likely be false positives. But that’s because the net would be wide.
No it is absolutely nonsense. You cannot possibly use NLP to evaluate novel claims and evaluate them for truthfulness. The NLP model couldn't know that. Social engineering is detectable because it usually includes something like a request for your personal information.
A novel fake news claim would not look anything like prior fake news claims. You'll have false positives, yes. You'll also have false negatives. Probably a lot of them.
A generic fake news detector is very different from, say, a detector of claims that Ukraine is a nazi state. The latter is easy to detect.
If you can use NLP for detecting social engineering scams, it can also be used to detect fake news. There will likely be false positives. But that’s because the net would be wide.