WARNING!! I ABOUT TO BLOW YOUR MIND! If you are in the real world you'd and look at the horizon it looks straight right? Wrong the earth curves, if you were to build the real earth out of 1 by 1 blocks there would still be a curve. Apply that physics to minecraft and you would have the same results. But if you were to travel to the edge of the map you get to a land of no physics but that land was suppose to teleport you to the opposite side of the world. But because you rarely reach the edge it's not implemented. Also because gravity is generated in the center of objects it means there would be a center point of the world. All of this means the world has a center. Your idea is us orbiting a square block, but if you had a square world the gravity would pull all of the matter back into a round ball. To have a square world you would need to have a very tinny mass so the gravity doesn't pulls it back to a round object.
Also your blocks are not totally square! If you could go down very far down to a block it has a very tinny curve in it. If you could make a long enough object let's say 2500 blocks long and when's back far enough and you still had the ability to see the entire length. It has a large curve.
All of this information means the world is round but made of square blocks.
Get ready to have your own blown. The world in Minecraft DOES have an edge. If if was a sphere and you walked in a straight line, you'd expect to eventually end up where you started. This is NOT the case in Minecraft. The fact that it's rumored to teleport you is moot. It doesn't do it, so whatever ideas were intended whether they be fact or rumor is absolutely pointless. Physics doesn't care about intentions, rumors or unimplemented ideas.
If you drop a marble on a table, it will fall according to the laws of physics. It doesn't matter that you intended there to be some second force acting on the marble as it fell. It wasn't there.
All evidence
CURRENTLY IN MINECRAFT shows that it's planet would be a cube or a flat square slab. Minecraft IS NOT EARTH. Real world physics don't apply anyways. The theme of minecraft is that everything is cuboid or is at least square.
We spin 1040 miles per hour or even faster. Some objects in space rotate 6 times per second! These objects are earth sided with 100 times the gravity but they're not disks. With a block hole you get spegetifyed if you get to close, that's the only place I can think of would stretch you with gravity.
Most galaxies are disc shaped.
Accretion discs are named such because of their shape.
Our solar system is a disc shape with only I believe Pluto being different and having an orbit that's angled about 40 degrees with relation to all the other bodies.
The matter stuck in a black hole's gravity tends to form a disc.
Angular momentum is conserved.