WhatsApp works on a new privacy option that will allow users to hide, from certain contacts, the last time they have connected to the application. This is an option that, at the moment, is in the testing phase.
The new tool was announced at the end of last March in version 2.22.8.9 of the Google Play Beta Program for Android of the application, in which new features were offered for the sections of the last connection time, information and profile picture.