The seventy-second closes the sequence at the final degrees of Pisces, which is the last five degrees of the zodiac before the circle returns to the first degree of Aries and the first of the seventy-two.
The closure is exact and it is a consequence of the arithmetic rather than a design. Seventy-two names, five degrees each, three hundred and sixty degrees: the last name ends where the first begins because that is what division without remainder does. The tradition reads the closure as significant, and assigns the seventy-second an office of endings and new beginnings, which is a reasonable interpretation of a position and not a property of the name.
Something similar is true of the sequence's other end. The first of the seventy-two, at the opening degrees of Aries, is given new beginnings, willpower and creation. Between them the two entries frame the list, and the framing is imposed by the zodiac rather than by the derivation, in which the first and last three-letter groups are simply the first and last the procedure produces from Exodus 14.
That is worth stating because the neatness is easy to over-read. The Exodus verses have no beginning-and-ending structure that corresponds to the zodiac. The names were generated in one order, the zodiac was laid over them later, and the correspondence between the ends of the two sequences is a consequence of laying a sequence over a circle.
None of which makes the reading illegitimate. It makes it a reading, arrived at by people who found a fit and interpreted it, and separable from the derivation that produced the names in the first place.