Finally somebody other than Ash suffers a release, it's been done a million times now and was completely unnecessary in XY and SM(Did they replace the team member? No! Did the Pokemon have to leave to let lesser focused on members of the team grow? No, Poipole needed focus unlike Rowlet and Lycanroc. Plus Ash was his family

)
Releases work best when you know the Pokemon well and it leaving actually serves a story purpose. Butterfree was Ash's first capture so it leaving pulled at your heart strings and also showed development for Ash as he let it go, and we actually saw how much he cared for him with his immediate trade back of Raticate.
Lapras was better off for it as it was evident they can't write sea worthy Pokemon on land at all, right Horsea and Goldeen? Plus he turned into the leader of his herd. Had he stayed he'd likely have been another Kingler, he served his purpose and his story was complete.
Weezing and Arbok were the TRio's literal first Pokemon like Ash and Pikachu, May/Torchic, Brock and Onix.... Misty and Staryu/Starmie? Them leaving them behind hurt a lot and still does. Chimecho got sick so James left him so he could recover, Cacnea got left behind as James wanted him to get stronger and couldn't do it himself, Dustox got released much like Butterfree and ironically got something Jessie regularly seeks after in filler episodes, love. I still cry watching Team Rocket say their goodbyes, Arceus I miss when they were allowed to bond with Pokemon....
Cut to now and oh look, Flabebe. You were caught then dumped at the lab and now only brought back simply to evolve and get released! K'bye!
....if they wanted to release a Pokemon of his, why not one of the Bugs or Dewgong? Something that actually showed up and could believably have a bond(as little as it'd be) with him. Why the **** should I give a damn about Flabebe?
How they should have handled a release was Dewgong falling in love yet again and they attempt at helping him instead of it being played for laughs. Dewgong winds up winning the girl in the end but has to be released in order to be with his true love out at sea where they'd be happy together, cue goodbye and it's gone! There, fixed it.
This episode was meh and makes me think more about why the heck they just don't make a AZ's Floette episode with a AZ tease instead. This at least would've been more interesting than what we got. Come on we don't want to wait the 3000 years for that to happen.
We'll never get that event. Stupid thing is that it still exists in the code while notched Pichu is forever stuck in HGSS