I think you could accomplish this more easily with a semi-evacuated floating tunnel heading east from the Galapagos Islands, and up the west slope of Chimborazo, whose peak is the closest to space of any other mountain on Earth.
That means it already has higher angular velocity by virtue of being close to the equator, and is further from the Earth's center of gravity by virtue of being situated on the equatorial bulge. The peak is also 45% the atmospheric pressure at sea level.
The floating tunnel would be about 1100 km, and then about 150 km up the volcano. At a constant acceleration of 30 m/s^2, relative to the launch tube, 1250 km of track gets you up to 8660 m/s after 289 s. Then you get 464 m/s from changing reference frames from Earth-fixed to Earth-relative at the peak of the volcano. Subtract about 1300 m/s for drag, and 7824 m/s is roughly a LEO at 200 km. About 3 Gs for about 5 minutes is easily tolerated by healthy humans in the correct orientation--we do that in amusement park rides for fun.
You seem to be confused between acceleration and escape velocity.
A Tesla Model S can accelerate at 1.14g while going from 0-60mph, but it can't continue that acceleration for long.
A dragster can accelerate at 5g for almost a second. It won't get into orbit if you send it off a ramp.
The train with a centripetal acceleration of 2g will not launch anything into orbit unless it can magically keep providing that acceleration to the vehicle.
On the other side, you don't need to accelerate particularly hard if you want escape velocity, you just need to get up to that speed after accounting for atmospheric drag. You could launch a winged rocket that accelerates at 1.12meters/s^2 -- in ten thousand seconds or so, it would be up to escape velocity.
I don't think the parent is confused, I think they are talking about the velocity you'd reach after being subjected to that acceleration over the whole 2000km track.
1G over 2000 km gets you to 6261 m/s, after 639 s. That isn't escape velocity. That isn't even orbital velocity.
But Fortaleza, Brazil, to Dakar, Senegal, is about 3100 km. 1G over that distance gets you to 7795 m/s, after 795 s. That can almost get you to a LEO, with a 40 degree inclination. You'd still need to overcome atmospheric drag.
Fortaleza, Brazil, to Libreville, Gabon, is 5350 km. 1G over that distance gets you to 11240 m/s, after 1045 s. That will get you into an orbit with 4 degree inclination, and after accounting for drag and the angular velocity at the equator, you might even still be at escape velocity after exiting the atmosphere.
it might have to be at the poles.
another option would be to build a bridge from south america to west africa, and at 1g you'd reach escape velocity.