I think the splash screen should only be a skeleton of the tab bar/nav bar. The icon might not fit the user chosen app icon, also it makes the app feel slower. Apple’s HIG also recommends the skeleton
images in the feed should have the full height (otherwise most memes and posts aren’t readable without a tab and dismiss)
I know HIG recommends the skeleton but I’ll have the same issue where that splash might not match theme chosen by the user and that’s even more jarring.
There’s a setting for this under Display > Full Height Images