Mailchimp merge tags and posting to social media

I'm creating my first email campaign with Mailchimp, and going with marketing best practices, I've personalized the top of the email with "hello fname", using the correctly formatted merge tags, of course. It works fine when I test it. When I started setting it up, there were some general campaign questions I had to answer, a couple of which were whether I'd like to also broadcast the email to Facebook and Twitter. Of course I do, thanks! My question (that I could not find in the Mailchimp knowledgebase) is if those merge tags will be replaced with blanks in the social media broadcasts (which is ideal) or if they'll just remain visible merge tags? Anybody here know?

Restated, in case the question is muddled, the top of my draft email says: Hello *|fname|*
When sent to my subscribers, it will look like this: Hello Sharon
When sent to Facebook and Twitter, I'd like it to look like this: Hello
and not like: Hello <<First Name>>