From NJEA:
Because the SEHBP has operated very efficiently and spent less than anticipated in recent years—partly as a result of changes negotiated and advocated for by NJEA—it has built up reserves in excess of what is needed to keep the plan solvent. Those reserves come from the premiums paid by employees and employers. The premium holiday is essentially a way to refund a portion of those premiums and allow employees and employers to share in the benefit of the lower-than-expected costs.
More info: NJEA
Details from Division of Pensions and Benefits (including school districts that are eligible). 12.9.21-SEHBP-premium-contribution-holiday
Article about the reduction in premiums and the premium holiday from Insider NJ.