Why is it important to be able to trace the pole connection on a meter back to the same type of pole at the electrical source?

It is important for polarity. In areas where neutral is grounded or earthed, it is essential to ensure that the neutral wire is not confused with a live or a hot wire. The live or hot wire could be connected to ground. In this case, fuse on transformer will not operate unless the fault is very close to the transformer. The fuses in the consumer's intake box will not operate