Apple Intelligence is training itself on the apps you allow by default. You can go to setings > siri > about siri, dictation & privacy, and switch that off if you wish. You'll have to do it app by app, one by one.
It’s basically for allowing the voice assistant team to improve recognition by collecting references data, and for using usage behavior decide how to best sort search suggestions, when you like to use certain widget, and who should be prioritized in share sheet for certain apps at certain times. It’s pretty rudimentary.