Yes, I agree that most steps in tango are walks from position to position without flight - I would actually say stable position to stable position. A very important part of that is not arriving past the stable position at the end of the step - if you arrive too far, you have to take another step in the same direction, which is called body flight.
But I think there are some exceptions where a different technique is called for. These have to do with body positions where the stable position to stable position, foot before body, method would not really work. One example is the reverse turn lady outside - there the movement through the outside step needs to be more continuous with the body bringing the foot as in the swing dances, rather than leading the foot as in most tango actions. Another is the step out in promenade - unless danced as a static point action, the step out in promenade really wants to flow right through to the step through in promenade. But the step through in promenade ends normally, in the stable position of the foot. If you were dancing something like a closed promenade, that would be espcially important as the step through continues the direction of the step out, but after the step through the direction changes abruptly to become a sideways action. Coast through the step through and your closure from promenade will be weak.