Was anyone notified while I did this?

Hello,

I had a doubt about my normal contact list and my Whatsapp contacts.
I was looking at my group chat yesterday and I decided to add some people in it to my iPhone contact list. Before that, only their phone numbers came up, and now they have been replaced by their names. Can they know I´ve added them to my contact list? They already had my number before that, as it was in the group chat, but I don´t know if anyone has saved me as a contact as well in their list.