Depends on the breeders cleaning procedures…
From what I understand IBD is communicable not airborne…So if nothing ever crosses between species the Pythons shouldn’t be at risk…
If the breeder doesn’t wash their hands in between each snake, uses the same sink, sponges, hooks, cleaning tools, etc for the two then yes the Pythons would be exposed to IDB if it is present.
Mites can also spread IBD from animal to animal.