In 1247 the whole world saw the Red Moon rise into the Middle Air. At first it could only be seen at night, but after 1275 or so, it could be seen during the day as well.
Remember, this unnatural and terrifying event could be seen throughout the world. The only historical event anyone could compare this to was the Sunstop in 375. That event heralded the birth of Gbaji and the terrible Chaos Wars.
The Malkioni saw the rise of the Red Moon as the rise of terrible evil. The Red Moon is NOT anywhere in any of the sacred texts or theories of sorcery. Its appearance was unnatural and wrong – clearly the result of insane magic or even Chaos. Nothing the Malkioni learned in the intervening centuries made this any better – the Red Moon was the result of a mortal (herself the product of a mad cabal) who turned herself into a goddess within Time.
It is entirely possible that the rise of Rokarism in Tanisor is the result of witnessing the Red Moon rise in the northeast. It may have also radicalized some Malkioni schools in Fronela.
Remember what a moon versus a planet is in Glorantha. We could just as easily refer to Annilla as a dead planet. There are myths of the Annilla, but she fell from the sky. No idea if she just hung there motionless like the Red Moon, she certainly didn’t have phases! Now we know she is associated with the Blue Streak, who causes the tides and maybe that is her.
In short there is no real objective reason to make a strong connection between the Blue Moon and the Red Moon. The Lunars do, and the cults are associated. But maybe that is a different association.