I can confirm peter shaw's observation for 1.14.4: Teleporting minecart and player together over a long distance will teleport the minecart, but leave the player in a phantom minecart he can't leave without teleporting/ender pearl on the original location. The issue is therefore not fixed as it is claimed here.
I can confirm peter shaw's observation for 1.14.4: Teleporting minecart and player together over a long distance will teleport the minecart, but leave the player in a phantom minecart he can't leave without teleporting/ender pearl on the original location. The issue is therefore not fixed as it is claimed here.