Right, but I can tell you from personal experience, Shortcuts is just like Workflow. Shortcuts run exactly the same way Workflows do: stepping through each step in the process. That may change, but for now its exactly the same way. If you don't believe this, check out this tweet from one of the Workflow team:
https://twitter.com/mattcassinelli/status/1022998764313665536
My main point here: don't get hung up on the fact that you do not have access to the Shortcuts app yet. If you perfect your skills in Workflow, you'll move right over without any hesitation when the Shortcuts app is released.
If you think you're missing the cool things demoed on stage at WWDC, you're not. Those things will not be possible until all apps are updated to the iOS 12 API and (most importantly) the app developers code in the necessary steps to "donate" intents (i.e., make discrete app actions available).