@Grunt from TRT mentioned above that some of it has to do with metal alloys that are used causing uneven weight. I’d also be really interested to hear about any other potential reasons from a manufacturer.
I wonder if the color of paint could have anything to do with it as well. Do different colors of paint weigh different amounts?! 
Anodization is not the same thing as paint. Ano should not add an appreciable amount of weight to a yoyo, to my knowledge. I would expect that Grunt is closer to the mark with his assertion that the alloy used is very slightly inconsistent when weight disparities are seen within a single run or between two runs.
I just ordered my Creep…
not a noob question at all, every yoyo is subject to manufacturing tolerances, as such every yoyo will be slightly different size and weight than all the others in the same run.
this actually applies to the vast majority of things that gets manufactured, not just yoyos
Also have to add in variances in bearings and axels, which might not have high tolerances.
Does anybody know the gap width and what alloy they used, 6061, 7075 or 7068?
Thanks