PorcelainVulpix
currently watching LOK
I don't think they care about fairness, unfortunately. But I also don't think that Haruka returned because of a "pattern". At that point in the series there was only one other female traveling companion who had returned to the cast for a few episodes, so it couldn't have been part of a pattern if it only happened once before. So I think that Haruka returned in DP because she had a goal that was the same as Hikari's, so she was simply the most obvious character to return.
I disagree. By the time DP came around, it was obvious they were going to keep having new female companions for each saga (not including gen 8) so I feel like they decided to establish the pattern there. I mean if Misty came back in AG, why wouldn’t May come back in DP? It just made sense. They could have easily done the Wallace Cup arc without May, I don’t think they just suddenly remember May is a coordinator so let’s include her for an episode.