I think that your example is not correct.
Tinder and a lot of others apps share information with Facebook about what you do by using their SDK.
Tinder and a lot of others apps share information with Facebook about what you do by using their SDK.
What I did do is add those girls’ numbers on WhatsApp - which is a Facebook property - and they suddenly appeared as friend recommendations.
But if there is any definitive proof it’s that I only was recommended the ones that I had messaged on WhatsApp, never those that I had only chatted up on the Tinder app...
But it may be very possible that they do a combination of everything to track you (whatsapp, instagram, facebook, oculus, apps that use the sdk...)