Generate Snapshot - Update Statistics on multiple tables (that I didn't add)

Hi,

We have 3 SQL instances as below.

- SQL 2014 is publisher

- SQL 2014 is distributor (remote distributor)

- SQL 2012 is subscriber

Then, when I add the new table into the existing publication, I found that the snapshot agent do the update statistics on multiple tables even some tables has already added into the publication before.

so that, Does the snapshot agent do the update statistics 

1. only the new table that we will add 

OR

2. update random tables

Thank you. :)