No. The code I gave was only if there were still a problem. If it's working, as I said there's no mention of hiding things in the manual. What you do while new content is loading is up to you, but you don't have to hide it or do anything. In fact, if you do .hide() it, you will have to .show() it later, or no one will see it. Some people like to put the word Loading in there, or a loading image (example using the text 'Loading . . .'):
But you don't need that.
$('#content').html('Loading . . .').load('<?php echo get_site_url(); ?>forgotpassword #fgp');