How to delay replication start
Got it. See my code, there is an option when creating the publication

EXEC sp_addpublication @publication = N'db_name',
       ...
    @immediate_sync = N'true'
    ...
GO


That's the equivalent of checking on the publication creation wizard the checkbox Create a snapshot immediately and keep the snapshot available to initialize subscriptions. 



That's why when running it, tried to automatically create the snapshot. And as last snapshot is from couple of months, there is lot work to do in the middle. Ran with false value and now everything is ok, runnig smoothly and without issues.