They don't have to release a beta for 7.1, so your logic is flawed.
They are going to re-introduce iCloud keychain, which was present in the iOS 7 betas but taken out in the GM. It's a major feature, and has already been tested.
Also, they don't need to release a beta for bug fixes. They really only release them to test new features, which, as I mentioned, was already tested in the betas.
this along with iOS Notifications on Mavericks seems like something that would merit a 7.1 update that wouldn't necessarily require a whole lot of beta testing since I believe it's already done.