He has returned.
The thing is, it's still the most showcased Pokemon all because of its Riolu days, even if it has failed to win several PWC matches.
It's like a reverse Torkoal. It's lost many times, but it appears a lot and takes priority over the others who barely matter (even if the amount of episodes for Ash's side is pretty low).
if any of Ash's pokemon were like Torkoal right now, gengar would own that title more than Riolu/Lucario since it's only had 1 on screen victory, and I really hope it improves because NO pokemon should ever be treated the way torkoal was.
So I take it despite it's performance against Volkner you don't believe it's any better than it once was?