Today, Apple released build 18E5140k of the iOS 14.5 and iPadOS 14.5 betas, which were originally seeded earlier this week. It's just a new build of the first beta, so it's likely that's all that's new are some important fixes and improvements. It's still exclusive to developers.
The big new feature in iOS 14.5 is that it lets you unlock your iPhone with your Apple Watch when your phone detects that you're wearing a face mask. It's the first solution that Apple has come up with for biometric authentication while wearing a mask, although obviously, you do need an Apple Watch. After turning it on, Face ID will attempt to recognize you, see you're wearing a mask, and then use the Apple Watch as long as it's close enough to your phone and it's unlocked.
For iPadOS 14.5, there's a new emoji search. With the ever-growing library of emoji characters, this should make it easier to find the ones that you're looking for. There's also a new horizontal boot screen, if that's something that you pay attention to.
These updates should roll out to those on the public beta pretty soon, and whatever bugs today's builds fix might be the reason that it hasn't rolled out. As for when they will roll out to the general public, it will probably be a couple of months.