After some deliberation, I think I may have figured out what this thing was supposed to be:
Looking through all of the toy concept model sheets that came included with my Karyuudo Fansubs torrent download of Beast Wars Neo, this one has the second-latest Takara date stamp of '98,11,13 (that is, November 13, 1998). All of the earlier-dated model sheets are toy designs for the series' main cast and the guest stars introduced in the first and second thirds of the series.
The only other toy model sheet that is dated later than this one is the following one dated '98,12,15 (December 15, 1998):
While it appears to simply be the toy design for
Eggleo/
Dark Eggleo, a closer look at the Japanese text reveals that it says "Unicron's minions", which is what the Blentrons were.
This, to me, seems like Takara had, at one point, considered using the Egg Beast molds for the third faction of the series before deciding on the Blentrons, and which they would eventually do in Kiss Players with the Sparkbots.
Of further note is that the text also mentions the mold being a sphere, as if to say that that's its connection to Unicron, who also turned into a sphere.
And what is the Retrax mold's main gimmick?
Looks pretty spherical to me.
Which now brings me back to the original concept in question.
Since this concept is dated later then the model sheets of all of the other characters who did appear in the show, but before the pre-Blentron "Unicron's minions" model sheet, and since this concept uses a mold that has a spherical configuration like both Unicron the Egg Beasts, I theorize that this Retrax retool was also an original concept for what the Unicron-aligned third faction was going to be.
This concept also resembles the Cyborg Beasts of Beast Wars II, which were upgraded Predacon forms created by Angolmois Energy. Since Beast Wars Neo retconned that into being Unicron's energy, it would make sense for Unicron's minions to look like those who had been previously upgraded by his power (as in, resembling the Cyborg Beasts).
In the end, Takara probably opted not to go with this concept because it was easier and more cost effective to just use the existing non-show Deluxe Fuzor molds that had just come out in Kenner's Beast Wars toyline that same year, and then probably came up with calling them "Blentrons" after deciding to use those molds for Unicron's third faction.
Congrats on completing Lio Convoy.
