The Personal Finance and Money moderator election is having its nomination period extended because there are only as many candidates as vacancies and they want to ensure a contested election.
While I think it's great to be looking for more candidates, S.E. could always guarantee a contest by including an extra option to indicate that a voter would prefer noone to be elected than any of the remaining choices. This option is typically called "None of the above" or "Reopen nominations" in elections where it is used. If it reached the threshold before enough candidates had been elected, then no further candidates would be chosen. The election could be rerun if necessary to get more moderators.
The current rules seem a bit artificial without this - it would for example be possible to have an election where all the candidates would be unwanted, as long as there's one more candidate than vacancy.