If I delete a contact from WhatsApp, will they see that I did so - briefly?
No, if you delete a contact from WhatsApp, the person you deleted will not be notified or see that you have done so. The action is entirely on your end and does not generate any notification to the other party.
If I delete a contact from WhatsApp, will they see that I did so - in detail?
If you delete a contact from WhatsApp, the person whose information you are removing will not be directly notified or informed of your action. WhatsApp does not send any type of notification to the user when their contact details are deleted by another individual. This ensures that users can manage their contacts list privately and without causing any disruption or confusion for others.
However, it's important to note that deleting a contact from WhatsApp will not remove the conversation history with that person from your device. The messages exchanged will still be visible in your chat list until you manually delete the chat thread as well. If you wish to completely remove all traces of interaction with this individual, you would need to perform both actions: deleting the contact and then deleting the chat history associated with them.
In summary, while the act of removing a contact from WhatsApp is private and will not alert the other person, it does not affect the visibility of past conversations unless you take additional steps to delete those as well.