Expect iOS 10.3.3 to Bring Bug Fixes
At this point, we expect the iOS 10.3.3 change log (that is, the stuff on board) to be pretty small.
Outside of the new iPad Pro wallpapers, iOS 10.3.3 beta testers haven't found much on board the iOS 10.3.3 beta. The first iOS 10.3.3 beta is very similar to the sixth iOS 10.3.3 beta.
Given what's currently on board the iOS 10.3.3 beta, we expect the official list of bug fixes and improvements to be extremely small.
We also expect the list to include specific fixes rather than general ones. That is to say that you shouldn't expect fixes for the battery drain and various Wi-Fi issues plaguing iPhone and iPad users on iOS 10.3.2 and below.
This could certainly change as the beta progresses but we typically see the bulk of upcoming changes emerge in the first beta release.