To people like them, regardless of the importance placed on the Demon Race, the Demon Race ultimately belongs to the losers — they are the defeated ones beneath them, and their sentiment is merely due to past sacrifices. It doesn't mean that they believe the Demon Race will have a chance to win.
Now that their descendants possess such ambition, it is naturally a comforting thing for them.
Though they have found some traces, the issue of the Demon Race has not yet truly occurred, so they only need to take some precautions, not considering it the most important matter.
Regardless of whether the Demon Race will counterattack, the situation in the Divine Land World has already evolved to this stage; a great war is inevitable and won't be delayed or disappear due to the Demon Race's emergence.