The news of his injury had to be kept secret. Otherwise, the forces suppressed by the Hall of Souls would definitely come for revenge!
The reason why the Hall of Souls was able to suppress many factions, and even control a few large factions, was because the number of Star Aperture realm and Creation realm experts in the sect was greater than most high-tier forces. The Hall of Souls could even rival three to five middle-tier forces combined. However, now that the bulk of the experts had been conscripted, the moment news that Hun Tian was injured spread, it was very likely that the headquarters would be attacked.
When the Divine Dragon family conscripted them back then, it was by show of force. Ten Star Aperture realm experts and one Sealed Gate realm expert came personally, so how could the Hall of Souls reject them?