I thought Filler episodes were episodes where:
1) No new Pokemon appear/No older Pokemon evolve
2) No new move is learned by a main-cast Pokemon
3) No important game/anime character is introduced
Since this episode includes two never-before-seen Pokemon, I'd assume it wouldn't be Filler since it serves a purpose of showcasing new Pokemon in the Best Wishes anime. Well, whatever. I'll go with Torpoleon and just say that we cannot judge if the episode is Filler or not just by the title. I'll agree to disagree basically :]
If this episode involves character devolpment, it's no filler. Look at the Zangoose/Chimchar episode in DP.
No new Pokemon appeared nor any old Pokemon evolved. Filler so far? Yes.
Nobody learned any new move. Filler so far? Yes.
No important/anime character appeared. Filler? Yes.
But Chimchar got devolped in this episode, with the Blaze incident, I believe and a backstory connected to Zangoose. I bet that some people will call it a filler, but we learned a lot about Chimchar.
This was a bad example, but it was the best I could find.
I don't think saying showcasting new Pokemon means it won't a filler. Then maybe episodes would be important because they showcast new Pokemon. Then probably 30-50% of the episodes, beginning from Episode 1 in Kanto to this episode, 600+ episodes later, in Isshu, would go from 30-50% filler to 5-10% filler.
If anybody devolps in this episode, like personallity wise or we learn backstory, like maybe from Dento or Iris, I won't call it filler.
I personally like to categorize fillers from exciting to terrible. A funny filler would be exciting and I wouldn't mind that, too much, while a boring filler would be terrible and that's what I don't want to see.
If this is a filler, and it happens to be entertaining, I wouldn't mind that. If this is filler is Johto-filler material, then I'll watch it and never look back again.