More likely Wu clan was the original owner of the techniques but had to hide in a backwater (remember he's an overpowered protagonist mentor plot wise) after suffering a defeat where all but their core techniques were lost.
Its weird how every world or area the MC goes to is ignorant and is a back-water, all because of the King of Everlore. Wu Yu is an 8th tier, and he is hulk smashing his way through everyone after hitting his 1 item powerspike.