Do you think the Celestial ponies would have had a gimmick?

[Galactica]

The fact that there are four in the set and that they (probably) have a similar gimmick to the Moondreamers indicates that they would've been slated for production around 1989. Before that, ponies were overwhelmingly six to a set, and Hasbro switched to three to a set around 1991, which gives us a Year 8-9 window for the Fairy Brights.

This is a good point! I think it's also noteworthy that the fairy brights are all earth ponies. In years 8-9 Hasbro still included unicorns and pegasi in the sets if they were made in the traditional molds. In year 10 they scrapped unicorns and pegasi altogether, with the exception of the paradise baby set.

So maybe these were not going to be made in the traditional molds?

I think there was a lot of speculation they were going to be in the flutter molds...

I own a custom set in flutter molds but I always pictured them in the Bride pose Hasbro favored in later years.

Oh yeah! Could be-  I wish we knew the designer on the project, or whether they ever made samples...

[lunar_scythe]

Most of the SHS poses were released in groups of 4, weren't they?

[Mermaid]

I always pictured them either in the color swirl pose or as flutter size!!

My guess is that they were developed later in the line and were canceled in favor of the color swirl ponies, due to the glow and shows and sparkle ponies being released before them maybe they thought whatever gimmick they had was too similar to the two previous lines and opted out for the marble effect as the main gimmick and designed the color swirl ponies!