The update's making its way to the phones right now.
There's a fair amount to unpack with this latest update, with one of the most notable additions being the May security patch. Having a secure Android phone is essential, and it's always reassuring to see OnePlus so on-the-ball with these patches.
As for user-facing changes, there's a handful of goodies to find with the OnePlus Launcher, including a new Toolbox Card in the Shelf, a section in the app drawer called Hidden Space, as well as support for editing dynamic app icons (such as the weather, clock, and calendar).
The OnePlus Switch app has received a minor UI update with some under-the-hood changes, and a long-time bug causing group MMS to not work has finally been patched.
OnePlus is rolling out this update now, and if you've already got your OnePlus 5 or 5T enrolled in the beta, you should receive an OTA update in the coming days.