General Discussion

That no damage to the mission or those participating in it would come once he blew the whistle.
However....
In the course of the review of "the foul", it is obvious there was a lot of OPSEC compromise and especially potential high level asset compromises to a hostile foreign power.
Who knows what other potentially classified conversations and "chat briefings" held on Signal by this group of morons were monitored or hacked into, especially since a few of them are known to be friendly to Russian interests.
Aggregation of "unclassified" or lower level of clearance information is just as harmful to National Security - like letting the GRU or PRC agents walk into the SCIF and sit down in the back for a cuppa while the Brass and NSA are sitting around the table discussing and projecting defensive technology and strategies for NATO and Taiwan.