When new hardware comes out, companies do not always get it right away. This only affects the latest iPad Pros, and not the previous ones.
There are plenty of apps that have not been updated to handle the new screen resolutions. In order to properly take advantage of the full screen on the new iPad Pros, the apps need to take into consideration the new home bar thing that hovers at the bottom. You need to make sure your UI doesn't merge into it so button pushes. It's similar to dealing with notches on Android phones. It took them awhile to add native support but they finally did with the most recent client release and it works well.
There's also a chance the shadow issue could be an iOS driver issue. In that case, there may not be a work around and they just have to wait until Apple fixes it.
If this fix requires a client update, you should know by now that SWGOH client updates are a pretty big deal. They're most likely not going to roll out a client fix for an individual bug unless it's completely game breaking. Client updates are usually reserved for new game features like game modes and QoL features. So they'll bunch all of those and bug fixes into one release. If some of the features in the most recent Road Ahead post require client updates, then hopefully the next update will contain a fix for the shadows and use the full screen of the iPad Pro 2018. I have a 12.9 inch model and the screen is big enough that I forget it's not taking up the full screen and the shadow bugs don't affect me game wise. Unfortunately, it looks like it affected someone for the Chewbacca event. That should probably should have been logged as a different bug.