Yes, the word "if" exists in that example. The distinction is closing out the request completely versus keeping it open. Removing the last sentence doesn't change anything.

It's like if someone invites you out to eat and saying, "No, I won't be there, but if anything changes, I'll let you know." vs "I'm not sure, but we'll see and I'll let you know!".

The latter encourages the subject to be brought up again.