Having experience integrating Unbounce these are served on a third party host and are therefore not indexed as part of your domain as they are blocked. I would be very wary of using these if you are considering creating a landing page that is very similar to the theme of another existing landing page within your main web page navigation.

As others have mentioned you may want to look at controlling how these are crawled, blocked or viewed by search engines if you are considering using these as part of any future strategy.