The most likely reason was that the Elders Guild had done a good job of keeping it a secret.
So, how did Beanna know?
This might have something to do with General Tarani.
Matthew had once heard about the dirty deeds of the Elder Council from Setrunk, and he also knew that there was a force within the Wood Elves that opposed the Elder Council.
The Windseeker General seemed to be one of them.
Perhaps she wanted to use Beanna's channel to remind him and the Alliance?
Perhaps this was a signal for help?
Matthew didn't continue to think about it.
Regardless of whether Tarani was asking for help from the Alliance, her worries were unnecessary.
Ever since the Blood Moon incident.
Matthew realized the Alliance's ambition and execution.
The legendary mages led by the Seven Saints were slowly cleaning up the various problems on this land.