I don't think anybody knows that for sure. There still appears to be a need for further 18's classes (based on how many backfill positions are needed), but that's just uninformed speculation.
Something I've been thinking about is that there are multiple eligible lists for this job. how or why, I can't say for sure. but my guess would be based upon the practical exam, as they offered them staggered at different dates.
As an item of public record, you may have already found this link online
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What it means, I couldn't say, but I know y'all probably dying to hear something. This is all I got for you.