There are two counterpoints that mean that this is unlikely to be what happens: Lego bricks are made to micron tolerances. When you add up tolerancing errors o

There are two counterpoints that mean that this is unlikely to be what happens: Lego bricks are made to micron tolerances. When you add up tolerancing errors over 10 or 50 bricks in a row the differences can add up and things don't fit. This is a big part of how Lego saw off the cheap competition - they were generally not satisfying to build. This is achieved with very careful injection moulding, and the only rapid prototyping tool at that level of precision is 3D CNC. There is more to the sets that pieces of plastic. Look at Warhammer - the figures are all plastic, they could easily be 3D printer, they might not look quite as good but they'd work just fine. Yet, Games Workshop sells set after set. Lego sets are also designed, come with instructions etc. There's more than just the components.