In previous iOS versions I've able to open a URL of the form "itms-apps://itunes.apple.com/artist/id463855590" and the App Store app would open at a page showing all my apps. This doesn't seem to work in iOS 12. I see a "Cannot Connect to AppStore" error message within the App Store app.
Using "https" instead of "itms-apps" takes me to the iTunes Store app and does show a list of my apps, but as a simple list, not the nice iOS 11 app store UI.
Opening an itms-apps URL for a specific app still seems to work (but not 100% of the time).
Is this just a temporary problem during the beta or are links to artist pages no longer supported?
The old URL doesn't work in the iOS 12 public release either. But I found that replacing "artist" with "developer" does work on iOS 12: "itms-apps://itunes.apple.com/developer/id463855590"
I tested the "developer" version of the URL on older iOS versions too and found that it worked as far back as I was able to test: iOS 9.3.5.
So, I guess we were supposed to be using "developer" for a long time but they also kept "artist" working until iOS 12.
I'm not sure if any of this is documented anywhere. The iTunes Link maker only seems to support links to individual apps. So, hopefully, this answer will be found by other developers in the future.