I guess we will be seeing some kind of "release candidate" build today, so with a "non-beta-buildnumber" like 13E209 or something. They have to have some "release-like" version ready to flash on the iPhone 5se and iPad Air 3's that will go for sale on March 18th probably; they cannot flash a beta on the devices.
And since we already have Feb 22nd, production of these devices has to be running at full speed as we speak.
So my guess: Something like 9.3 build 13E209 as "beta 4" today which becomes the final version about two to three weeks later (as they did with iOS 9.2, here too the "beta 4" became the final version without a changing the build-no).