"So it fall at the speed where the forces match."
does this mean that as the magnet falls it creates electron migration to one spot in the tube,opposite the polarity of the magnet.....which slows it down
Nope. No electron migration and gross electric field attraction from electron concentrations. Just magnetic fields - and forces on electrons (in the pipe and the magnet) when they move relative to the fields.
The electrons go round-and-round in an eddy around the place where the mag field from each pole penetrates the pipd's metal, as the magnet's pole slides down the pipe. The circulating current creates a magnetic (di)pole in the conductive metal of the pipe, which attracts the pole of the magnet. The resistive losses from the current cause the induced pole to lag behind the magnet in its travel, pulling it upward, in an electromagnetic equivalent of fluid friction.
(Conductors where current can flow tend to "pin" the magnetic field passing through them, resisting any change to it. They absorb the mechanical energy used to drag the field through. Current that goes through an external circuit can dissipate the power there - that's a generator. Current that travels in little loops through the conductive material dissipates the power in resistive heating there - that's eddy current losses {in thick wires or metal flux-path cores}. Slicing the metal thinner (at angles other than perpendicular to the mag field) breaks some of the parasitic circular paths, reducing their contribution to losses and drag - that's laminating the cores, or winding the coils with thinner wire N-in-hand, to reduce eddy current losses.)
The faster the magnet falls, the stronger the induced field from the induced current in the pipe, and the harder it pulls to retard the falling magnet. The magnet's speed stabilizes when the strength of the retarding magnetic pull matches the pull of gravity.
