wasn’t the snackdown parallel round rated for all?
It is written that rating will change after long challenge
Yes, it was.
The ratings have to be calculated in the order of the starting times of the contests. So the contest which started first has its rating calculated first, even if it ends later. Hence, in this case, the Long contest’s rating will have to be calculated first, then the Elimination rounds, and then START19.
And because of this, the ratings of the short contests can also be calculated only after the Long contest ends.