Okay, this is something I'm very passionate about. I have a very strong opinion on this.
Why does everyone always assume that "A bunch of other things we don't need to mention," is meant to say that no one cares about the themes they flashed? That line has always meant "themes we don't have the time to mention," because all that scene serves as is exposition explaining the threat facing the LEGO world.
For the purposes of the movie, all it wants to focus on are the themes it included: Wild West, City, Cloud Coocooland, all those main ones shown. The ones in Will Ferrell's diorama. And it would be at the detriment of the movie to attempt to include every single possible LEGO theme because that would be too much for the movie to handle and still have a clear focus. It was the right call.
So when Wyldstyle is explaining to Emmett what is going on, that entire little sequence of extra themes is a nod to the much, much, much greater and larger LEGO universe that the film simply can't focus on. And Bionicle being included in that I see as an honor. They bothered to even include the theme as a part of the larger universe, they acknowledged how important it really was to the company, and they know how important it is to fans.
You know what else was included in that sequence of themes? Pirates, Castle, Vikings, Minifigs, Friends, Speed Racer, and Fabuland. Two of those are original System themes, Vikings was a later off-shoot of Castle, Minifigs is extremely popular, Friends is the flagship girl-focused theme and a major focus of The Second Part, Fabuland was once a main young-children's theme, and Speed Racer, while obscure, represents the larger world of Licenced LEGO themes.
So please, please, stop assuming that scene was meant to make light of other LEGO themes. You really think LEGO would consider Castle and Pirates, two founding LEGO themes, something not worth talking about? I consider Bionicle being placed there an honor and a tribute, even if it was for only 8 frames.