Vlad I respect that. However, nothing prevents you to let the final user chose wether he/she wants to send personal information to a 3rd party.
If you really care about privacy, setting Apple Translation API as a default while proposing other services (e.g.: Bing Translate, Amazon Translate or Google Translate) may be a great idea. Ultimately, you let the advised user make his choice while offering a privacy-respecting solution to neophytes.