Well, what is the worst that could happen?

Even if it is the identical gear, you probably would get the same value but you are sure that it is correct since you calibrated it. On the other hand, not doing the calibration because you think it is the identical gear you could get over or under extrusion and are wondering why it happens because “it should be the same gear” and possibly look in the completely wrong direction trying to fix the result.

There is not really any harm in checking and being sure instead of assuming and then having to deal with the result.