We develop a banking app for families (parents and kids). 2 weeks ago we had to remove the possibility to pick phone contacts to invite other family members because Google claimed we were uploading contacts to our servers (which we did not). We appealed and it did not work. We then complied with their request and added to the privacy policy they we have access to the contacts and we might process them, and yet Google…
Did you ask permission to access all the user's contacts, or open a contact picker to let them pick a single contact?
In a similar way you could (in iOS) for this same feature just popup the share sheet to send a message. Though I am not familiar with the Android analog.