When will the update will be available for j7 pro

Why the one ui is not available for all country and all oreo devices

Why it takes so long to update Samsung phones to Oreo and why in the Oreo scheduleThey didn't write J5 2016 and I found Someone who has that phone and had the update and I have J7 pro and didn't get the update

Why they are going to install it in February 28 Why are they going to take all that timeI hope they make it before that date

I hope Samsung make Oreo update for J7 Pro