Update JFBCComments for improved Comments Box and deprecated XID

Yes and no, but it also depends on how you're inserting the comments:
Module
If you're using the Comment Module, if you leave the href parameter blank, the Comments will always be for the page its shown on. This is good if you want a unique comment box to appear on many pages.

If you specify an href, all comments will be for whatever page you specifically specify. This is good if you have, lets say, a multi-page article or other content that could be grouped together. The Comment box will show on all these pages with the same comment box for each.

Content Plugin - Automatically into Articles
Yes, this should remove you from needing to manually manage the xid/href from your articles. For blog type views, we'll always link to the best URL for the individual article we can determine. That way, in the blog view, or the article view, you should always have the same comment box for that article.

Hope that helps explain.