I manage applocker win10 packaged app rule policies from a win 2016 server. It's been awhile since i set it up, but I believe what I did was export my existing applocker rules before there were any packaged app rules (right click applocker in screenshot, export policy). This gives you an xml file.
Then I opened up group policy management editor and imported that xml on a win10 1709 client running the group policy management editor in the same applocker location placing a local copy of my rules on that client. I edited the packaged app rules on the client to block all the things I wanted to block, and then exported the new xml from the client and imported it into the server setting up those rules for the whole OU.
Unfortunately, you can't just edit packaged app rules on the server because win 2016 server doesn't have the packaged apps to point the server to block it. The export/import/export/import definitely makes it more time consuming that it should be, but if you block the app store (we do), it should only change with windows feature updates.
See my screenshot for the app rules. I believe you could also just edit the xml with the app names you're trying to block if you're very careful, but one typo could make that hard to maintain.
Please see attached screenshot and mark this as a solution if it helps you.