You can add profiles for living people but they will go unlisted and NOONE will be able to see them except for the profile manager and anyone on the trusted list.
I choose not to make profiles for living people (and this includes Notables) since noone can see them so I dont see the point.
There are some situations where an unlisted profile is useful, but it is not required.
As an example, my (currently living) mother does have a profile, but she is unlisted because I need her to link me to my grandmothers family.