Thanks for asking.
It is true that generally theme updates also comes with latest version of bundled plugins. However on the other hand please note that as and when required we rollout updates only for bundled plugins also. It's a good idea to keep website (core WordPress, themes, plugins) up to date so as to take advantage of new features, bug and potential loophole fixes. Running latest version of theme and plugins (that we rollout time to time) has other benefits communicated via our changelog page. For ease of use we maintain a version compatibility guide and suggest customer to always check the same for comparison:
I suggest you to refer our theme and plugin update guide as it has all the necessary details required to update theme and bundled plugins to make the process more seamless:
Just to summarize, you really don't have to wait for theme update to run latest version of plugins. We keep on releasing updates for the bundled plugins. If you spot a new version for a plugin as mentioned in version compatibility guide, go ahead and update the same by following the steps mentioned in our theme and plugin update guide.