The sect's elders were surprised because they did this mission that was supposed to be difficult very quickly when Lu Bi told what happened they were even more impressed and had even forgotten that Zhang Yi had also cultivated mental energy when he arrived so quickly to the Soul Refinement realm.
Still, that had been a good thing for the sect that had to clear their territory from members of the soul-eater organization and now they thought it could do a great job.
Another thing they realized was that they had to give more difficult missions so that Lu Bi could teach Zhang Yi some things, so despite being risky, they gave a mission to chase and kill a group of Sword Sect deacons who had fled after being discovered.