Racing themed costumes. Seems kinda out of place for me.
Look at them in the same way you looked at their past themes like Wedding clothes and Handsome Ladies(in the case of Prince's Frontline) and there's likely the reason being that they're dressed for undercover Spec ops.
Unlike most mobages, there is generally a fairly good reason behind it for most of the themed sets in this game instead of just pumping out bikini sets for the sake of delivering the fanservice.
Racing themed costumes. Seems kinda out of place for me.
Well, its a filler procurement pool, one which will most likely not have any Live2D costume in it and eventually be added into the Radiant Collection at a later date. Though my statement is gonna be invalidated when they fully showcase all the costumes later (They dont do showcases on weekends) and one happens to have a Live2D costume, then its just gonna be the same as the rest of the procurement pools, where one will be sacrificing their wallet for pretty dresses for their T-dolls.
Racing themed costumes. Seems kinda out of place for me.
G&K canonically does a lot of work for the civilian sector, for example the wedding costumes gacha was for Griffon being hired to have their T-Dolls act as wedding dress models. The Singularity event also throws in a passing mention of there being "Automated Racing Tracks" as a hobby, so racing as a sport is still a thing, and thus hiring T-Dolls as race queens makes perfect sense.
Unlike most mobages, there is generally a cheap excuse behind it for most of the themed sets in this game that can't really hide the fact that it's all for the sake of delivering the fanservice.