WhatsApp introduces another option that many will like
This feature is actually identical to the one about hiding stories.
The latest beta version of WhatsApp for Android has a new option to hide the "Last seen" status from certain people. WhatsApp has been actively developing this feature for several months and it is now finally available to a number of people. This feature is expected to be part of a stable WhatsApp upgrade soon, which means it should be available to all users of this app soon. This "soon" with WhatsApp could still mean "in a few months" because WhatsApp is known to be careful about adding new things to a stable upgrade.