Typically themes will continue to work on new versions of WordPress. Usually the only time we need to make an update related to a new version of WP is if there are deprecated functions no longer supported in the new version. Even this is very unusual. You will probably be fine.
Thank you for being a part of Runway. We hope you have a great experience and together we can make Runway one of the best additions to the WordPress ecosystem and theme development. We're excited to have you here!