These ambitious visual effects would have made the setting and characters more unique. But LoMN is a low budget film rushed to meet a deadline, and it already juggled way too many ideas anyway. It's a shame but also understandable that many effects couldn't be realized.
This was not replaced with a simpler effect in the final film, the scene was simply abandoned. The Troller sequences, featuring a giant beast swimming in sand, would have also happened around this part of the film, likewise requiring elaborate sand effects. That idea was cut too.
Several elaborate animation effects were planned but ultimately simplified or removed from Legends of Metru Nui, presumably due to budget/tech/deadline issues. They include kinetic display screens forming the shape of Turaga Dume during public announcements.
The Dume-Makuta reveal was also planned to be done with a mirrored kinetic display. Not sure how that would work or why a mirror would be designed like this, but it partially explains the conceptual origin of the mirror seen in the film that ripples like liquid.