While it might seem to be like only a few minutes had passed since Devon's meeting with the old man, and they couldn't be any much difference that could possibly occur in the ominous cave, to be honest, a lot of things had happened.
Apart from the drastic takeover of the ominous cave. During the moment when the old man wasn't in control of the cave, the situation in the ominous cave underwent a huge transformation, as the control of the cave was resumed by the divine beasts.
The divine beasts very much knew about what the other beasts were planning, and because they had been restricted all these years they were simply unable to get the truth of the matter out of the world.
But now that they wasn't anybody holding them down or any aura pressuring them, they were free to do as they wanted in the ominous cave. The beasts knew that an opportunity such as this one wouldn't arrive anymore, and so the beasts used this chance they were given to the fullest.
