No - the file uses links methods to update the table so you *shouldn't* need to reindex - I use a lot of files like this for updating the products on my site and they all seem to appear in the search results ok without reindexing.
Edit: Actually, you will need to add a weight to this new field so that it is included in the search results and I think this might need a reindex - sorry.
Edit: Actually, you will need to add a weight to this new field so that it is included in the search results and I think this might need a reindex - sorry.