Re-initializing is only required for Merge Replication and more to it if the following conditions are true :-

From BOL

1. If an article is a parent article in a join filter or logical record relationship, the relationships must be dropped first, which requires reinitialization.

2.If an article has the last parameterized filter in a publication, subscriptions must be reinitialized.

If you have snapshot or transactional replication then you need not worry. Unless you want to synchronize subscriber with the new publication.