Autogrowth and Merge Replication
Changes to the storage layer of a database, that is also a Publisher in a replication topology are not replicated to Subscribers. The only thing that can be replicated are those objects defined as Articles. 

For example, you can change the autogrowth setting of a given database data file at the Publisher without concern for the Subscribers. You can think of the database storage layer as an abstraction. It has to be because you may be using different storage sub system at the Publisher and Subscriber, requiring different data file placement etc.

This particular type of change can be applied without the need to reinitialize replication.

(For interests sake: If you were using Database Mirroring, then DDL changes of this specific nature would make it to the Mirror. Worth noting because Publishers are also often Mirrored in some environments.)