When using user-id feature in Google Analytics, does the
userId need to be set in every session in order to tie sessions to the same user?
I see that there is a session unification option that connects page views from before
userId is set to the same session, but haven't been able to find documentation about whether multiple sessions are unified to the same user without setting
userId in each session.
For example, a new user navigates throughout the site, then submits a form, after which a unique id is generated and
userId is set.
The next day, the same user returns to the site without performing any action to uniquely identify them.
Will this second session be tied to the same user when reporting on the user in Google Analytics?