Updates of system libraries there are definitely a plus.

However, besides the OS itself Apple doesn't do anything about app security. Not only they don't require unbundling, they don't even support it. Even if you use dynamic libraries in your app, they will be bundled with your app, and never updated separately.

From App Store perspective there's absolutely no difference between a Swift app diligently split into frameworks and a Rust monolith library. They treat both as an opaque bundle.