Not trying to defend them but if the reason for the raid was classified, they couldn’t disclose it to those not cleared to see such things.
No, they don’t have to reveal the contents of the classified material, but the warrant should clearly show evidence of criminal activity (”probable cause”) regarding specifically-identified classified documents, like a serial number or something for specificity, again, without reveling the contents.
Judge Reinhart was previously an Assistant District Attorney for South Florida, involved in the Jeffrey Epstein coverup. It is alleged that the Israeli government government intervened on Epstein’s behalf, and thus classified documents would likely be involved.
Perhaps Trump had the client list of Epstein and Maxwell. That is unavailable to regular citizens and voters.