My guess was that's it's a alterna x thayeri milksnake phase also.
I hate to see snakes misrepresented by sellers, because it's not fair to the person just new into the hobby or doesn't know enough about the species, thinking that it may be cool morph, and later they find out they were swindled.
There's one here in the faunaclassified under kingsnakes, Variable Kings **Sub-Adult Pair**.
link
I've been looking for a really nice '03 or '04 female thayeri for my male. I've posted twice on this add saying it was misrepresentation or not a truly a variable thayeri kingsnake. I even reported this add nearly two weeks ago and nothing has happened. Seems like this is a BOI incident waiting to happen when the buyer learns it's a subspecies cross and not a true thayeri pair. I was very disappointed to see and like that on this site. Makes me question the honesty and intregity of the seller Prehistoric and knowing I would never purchase anything from them or their company.