For anyone curious, the controversy around his inclusion in Cat Shows was because he was incredibly dominant in the first few shows he was put in. So much so that other Maine Coon breeders competing in the same shows complained to the organizers that while tri-color patterns are acceptable in female Maine Coons, they are ambiguously unaccepted in males.
Purebred cats in the cat show circuit have to be fertile. They can't be desexed (spayed or neutered) and they can't have genetic conditions that would render them infertile, sterile, or unsuitable for breeding purposes. The point is to identify the best individual examples of a breed to maintain or improve the breed over time. It's eugenics, but those are the rules.
Essentially all male tri-color cats are sterile due to the fact that the genes for orange and black color in cats are located on the X-chromosome. Male cats typically only have one X-chromosome so typically can only have either black OR orange coloration (white fur and dilute colors are actually caused by a pigment suppressing gene that is located on a somatic chromosome, and the pattern of white patches is controlled by yet other genes).
So, typically, a male cat that has both black and orange in his coat has to have an intersex condition called Kleinfelter Syndrome, where his sex-chromosome genotype is XXY, rather than the normal XY. The extra X-chromosome renders these male cats infertile or sterile.
But Dawntreader Texas Calboy (DTC) is not an XXY male. He is a chimera!
Basically, very early on in development two male embryos in DTC's mother's uterus fused together. This happened so early that the new chimeric embryo developed into a normal kitten. But, because one of those original embryos had a orange X-chromosome and the other had a black X-chromosome, DTC was born with a tri-color coat.
His breeder assumed he was sterile and left him housed with her female cats without neutering him. When some of his female roommates were found to be pregnant, the breeder decided to take DTC to the vet and look deeper.
When she discovered that this beautiful cat was a chimera, rather than intersex, she decided to start entering him into the shows her other cats were in, and he started winning A LOT.
But when those jealous competitors complained DTC was barred from further shows on the basis of his coloration being a "defect" that was "undesirable in the breed".
But chimerism cannot be passed down! It is a random, extremely rare event that happens after fertilization.
Basically, jealous rival Maine Coon breeders nit-picked and rules-lawyered an exceptional cat out of competition on the basis of his gender presentation.