Yes, they send your queries out to their servers (not to be confused with sending information about files on your machine out) but the 'session key' they use is

Yes, they send your queries out to their servers (not to be confused with sending information about files on your machine out) but the 'session key' they use is apparently not tied to your identity by them or third parties they work with. In their words: You can always opt out of Suggestions and continue to use Spotlight solely for local search on your device. You are also free to opt out of having Spotlight use Location Services any time you want. If you opt out, Spotlight will still use your IP address to determine a general location to make your searches more relevant. Unlike our competitors, we don’t use a persistent personal identifier to tie your searches to you in order to build a profile based on your search history. We also place restrictions on our partners so they don’t create a long-term trail of identifiable searches by you or from your device. https://www.apple.com/privacy/privacy-built-in/ https://www.apple.com/privacy/privacy-built-in/