Why did Apple do it, though? To create precisely this kind of cognitive dissonance. It's not Apple that's observing you. It's the government. Apple has basically created an API for government surveillance and can now say "see, we don't collect the data. We don't even know what big brother wants to know about you."
Apple just side-stepped the question on how to reconcile trust in propietary software and surveillance requests from the government. And everyone who tells you that it's not guaranteed that this feature will be extended to texts, spoken language, and other contents, is not worth talking to.
We now live in a world, where our personal computers come with "AI" that detects illegal use of those computers and automatically turns us in to the authorities. This general pattern won't disappear, ever. In a couple of years you will have to carefully consider every word you say in a car, every movie you watch, every website you visit, every program you write, because some neural net will use it to create a fingerprint that might be classified as illegal behavior.