Yes, Users will be set back to 0...but...If you go to
Thanks/Like Maintenance and run each item everything will come back
The only other thing is the Thanks / Like in the users Profile as the new default feature of Recent Entries is 30 days. If you want some of these back go to the
Thanks/Like Settings --> Scroll down to the bottom see...
Recent Entries and perhaps change to 365 days or the number of day you would like...
Edit: better yet what Fillip said...I didn't see it his post as I was typing!