Zhang Yi had a reason for not saying that the divine plane situation had resolved and that the demons would attack the divine plane, it would take a long time to convince sects who were in isolation about it.
Even more, because they had forgiven the beast sects that invaded the divine plane because of Zhang Yi's agreement with the divines of the Divine Sanctuary of the Beasts, and even if luckily the divine plane sects decided to come out of isolation to fight against the demons, they might want to attack the beasts for revenge.
In addition, the sects that went into isolation on the middle and right sides of the divine plane were much more affected by the war and more than half of their sect had been destroyed, so Zhang Yi thought it would be pointless to wait for those sects.