Having released iOS and iPadOS 13.4 on March 24 with big new features like trackpad and mouse support for iPads and iCloud folder sharing, Apple is moving on to its next minor release.
Apple released iOS 13.4.1 without a beta test, and has now jumped to iOS 13.4.5. That doesn’t mean we won’t see minor point-releases, only that if we do, we can expect them to be such minor bug or security fixes that Apple would directly release them without an external beta test. We may not see any other significant releases beyond 13.4.5—Apple has never gone beyond a point-five release in the past. After this, it's likely on to iOS and iPadOS 14 beta testing.