In the case of Apple it's much more obvious, when most of your revenue comes from hardware (and now also 'services') you don't have to mine your user's data for ads.

WhatsApp introducing Signal-based end-to-end encryption after it was acquired by Facebook was definitely surprising. I guess they can always switch to on-device profile creation :p. I trusted Whatsapp as a separate entity (low costs, yearly fee). Facebook, not so much.